In ancient Greek literature the concept of ‘service’ was expressed in many terms, for example, therapeuô : be an attendant, do service; douleuô : be a slave, serve, be subject; leitourgeô : serve a master, perform public duties; latreuô : be in servitude, serve.  In this article I intend to present an overview of the concept as expressed by the verb diakoneô  and its cognates diakonia and diakonos  in the New Testament. This word-group is entirely unbiblical  and non religious that is, not employed in the Greek Old testament except for a few times in a secular sense and in extra biblical literature it never includes association with a particular dignity or position. 
The verb diakoneô  primarily means ‘to serve at table’ and was extended to include the more comprehensive idea of ‘serving.’

Paul 
The gathering and delivering of the collection for the community in Jerusalem was a particular service which played a  special role in the life of Paul. 
In 2Cor 8.19f Paul expresses his part in this connection by the verb diakoneô - [v.19] “he (an unnamed companion of Paul) has also been appointed by the communities to travel with us while we are administering (diakoneô)this generous undertaking for the glory of the Lord himself and to show our goodwill. ” and again v.20 “...this generous gift administered (diakoneô) by us.” The collection for the impoverished of Jerusalem (Rom 15.26), was decided at the Jerusalem gathering (Gal 2.10) which Paul undertakes with enthusiasm, possibly also hoping that this good-will gesture would bring closer together the two, Jewish and Gentile,  sectors of the movement.
In Rom 15.25  Paul tells the Romans about his desire to visit them on his way to Spain and at the time of writing he is about to go to Jerusalem with aid to that community, literally “serving [diakoneô] to the saints”
This  assisting, rendering aid is almost a technical expression in Paul for the contributions of the Gentile communities to the Jerusalem community, thus the term diakonia  with the meaning of ‘relief’ is used for the collection. 
Paul, besides fearing  attacks upon himself of the unbelieving Jews, also has doubts whether the ‘collection’ as peace offering of the Gentile communities which he was bearing to Jerusalem would be accepted as such by the Jewish Christians,  “that I may be rescued from the unbelievers in Judea, and that my service/ relief [diakonia ] to Jerusalem may be acceptable to the saints,”(Rom. 15:31)  Paul also commends the Macedonians who out of their poverty contributed liberally towards this project and  “begging us earnestly for the privilege of sharing (koinonia) in this service / relief (diakonia) to the saints--” (2Cor 8.4 cf. also 9:1, “service [diakonia"] to the saints”). Paul exhorts and encourages, by different means, the Corinthians  to be generous in this undertaking. The relief to the Jerusalem community is considered also as service to God, [v.12] “for the rendering (diakonia) of this ministry (leitourgia) not only supplies the needs of the saints but also overflows with many thanksgivings to God.   [v.13]  Through the testing of this service (diakonia) you glorify God by your obedience to the confession of the gospel of Christ and by the generosity of your sharing with them and with all others,” (2Cor. 9:12,13)

The Service of Evangelization - Paul considers his work as an envoy of Christ as a ‘service’ which he expresses in different ways. In 2Cor. 3:3 he describes the Corinthian congregation as  “a letter of Christ, prepared (served, diakoneô) by us, written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of human hearts.”  In this metaphor Christ seems to be the author and then what is Paul? Is he  the amanuensis who ‘quilled’ the ‘letter’ or the ‘postman’ who carried it to its destination? Whatever it is the main sense seems to be that Paul and his colleagues were Christ’s assistants in bringing the ‘letter’ into existence by converting the Corinthians. 
In 2Cor 3.6 Paul calls himself “servant (diakonos) of the new covenant” which he continues to elaborate by contrasting the two dispensations, the Mosaic law and the Gospel, in terms of ‘diakonia’, - [v.7]   “Now if the service (diakonia) of death, chiseled in letters on stone tablets, came in glory so that the people of Israel could not gaze at Moses' face because of the glory of his face, a glory now set aside, [8]   how much more will the service (diakonia) of the Spirit come in glory? [9]   For if there was glory in the service (diakonia) of condemnation, much more does the service (diakonia) of justification abound in glory!”    For Paul the Law was a helper to sin which in turn brings death (cf. Rom 7.7-11), the New Covenant assists in bringing about righteousness or justification. Furthermore in 2Cor. 5:18 he writes,  “All this is from God, who reconciled us to himself through Christ, and has given us the service (diakonia) of reconciliation;”  Although the first ‘us’ refers to the Christians the second seems to refer to Paul and his colleagues or other evangelists as can be seen from the parallel in the next verse [19] “that is, in Christ God was reconciling the world to himself, not counting their trespasses against them, and entrusting to us the message of reconciliation.” thus  “reconciling the world” corresponds to the first ‘us’  and  “entrusting to us the message of reconciliation” corresponds to “has given us the service of reconciliation.” Paul’s work is considered as assistance or instrumentation in the process of God’s reconciling of humanity to himself.
Paul’s task as a preacher of the gospel is termed ‘service’, diakonia. “Therefore, since it is by God's mercy that we are engaged in this service (diakonia), we do not lose heart.” (2Cor. 4:1)  “We are putting no obstacle in anyone's way, so that no fault may be found with our service,” (2Cor. 6:3)  “I robbed other communities by accepting support from them for your service” (diakonia) (2Cor. 11:8)
This diakonia of Paul is directly connected with his envoyship in  Rom. 11:13,   “Inasmuch then as I am an envoy to the Gentiles, I glorify my service (diakonia).”
Those engaged in this work are called ‘servants, assistants’ (diakonoi). 
Addressing the factions arising among the Corinthians from attachment to personalities, Paul insists that the persons considered by the partisans as some heroes are but assistants of God in ‘planting’ and ‘watering’ the community, “but God gave the growth.”(v.6)  “What then is Apollos? What is Paul? Assistants (diakonoi) through whom you came to believe, as the Lord assigned to each.” (1Cor. 3:5)
These servants are sometimes qualified by ‘of God’ or ‘of Christ’, “but as servants (diakonoi) of God we have commended ourselves in every way: through great endurance, in afflictions, hardships, calamities...”(2Cor. 6:4) and again, “Are they servants (diakonoi) of Christ? I am talking like a madman-- I am a better one: with far greater labors, far more imprisonments, with countless floggings, and often near death.”(2Cor. 11:23) 

Christ as well is called diakonos in Paul.  “For I tell you that Christ has become a servant (diakonos) of the circumcised on behalf of the truth of God in order that he might confirm the promises given to the patriarchs,” (Rom. 15:8) and, “But if, in our effort to be justified in Christ, we ourselves have been found to be sinners, is Christ then a servant/ helper (diakonos) of sin? Certainly not!”(Gal. 2:17)

In 2Cor. 11:15 we find Satan’s servants,   “So it is not strange if his (Satan’s) assistants (diakonoi) also disguise themselves as assistants (diakonoi) of righteousness. Their end will match their deeds.” 

The governing authorities, mainly the Romans throughout Paul’s world are considered God’s assistants, “for it is God's servant (diakonos) for your good. But if you do what is wrong, you should be afraid, for the authority does not bear the sword in vain! It is the servant (diakonos) of God to execute wrath on the wrongdoer.”(Rom. 13:4) One wonders whether Paul knew that these diakonoi of God executed Jesus of Nazareth, or then, if he knew, in Paul’s view, would Jesus be a wrongdoer? And, if the tradition regarding Paul’s beheading is correct would he consider himself justifiably executed?

The sense of serving to provide domestic or other personal service to an individual is found in Phlm. 13,   “I wanted to keep him (Onesimus) with me, so that he might be of service (diakoneô) to me in your place during my imprisonment for the gospel.” This does not seem to be a case of help in the work of evangelization, in this case Onesimus would have been kept by Paul as his own slave.

People helping in the projects of the communities are indicated in several passages. In Philippians Paul makes a special mention, at the very beginning of the letter,  of those who were instrumental in procuring for him the pecuniary contribution of the Philippian community whom at the end, in 4:10-20, he makes it a point to thank and praise for their gift sent to him by means of Epaphroditus (2:25). “Paul and Timothy, slaves of Christ Jesus, To all the saints in Christ Jesus who are in Philippi, with the overseers (episkopoi) and assistants (diakonoi).” (Phil. 1:1)
In 1 Corinthians he mentions a whole household of helpers, “Now, brothers, you know that members of the household of Stephanas were the first converts in Achaia, and they have devoted themselves to the service (diakonia) of the saints; (1Cor. 16:15) The ‘saints’ here are the believers in the community not those of Jerusalem. Then in Romans he mentions an individual female assistant of the community,   “I commend to you our sister Phoebe, an assistant (diakonos) of the community at Cenchreae...”(Rom 16:1 ) In Greek the noun diakonos, not having a feminine form, is used for both genders.

For Paul the various functions and activities in the communities were gifts of the Spirit. In 1Cor 12.4-6 Paul states that in the community there are varieties (diairesis also means  ‘distributions’) of gifts (charismata), of services (diakonia) and of activities (energêmata) but in the following list he makes no distinctions of any such categories, for Paul these are all “manifestations of the Spirit for the common good.” (v.7) Diakonia here has the general meaning denoting any service in the Christian community.  In Rom 12.6-7  diakonia  itself, possibly denoting a particular activity though not specified, is listed among the gifts (charismata), placed between prophecy and teaching, [6] “... if prophecy, in proportion to faith; [7]  if service, in serving (both diakonia); he who teaches, in teaching;” 
 

The Gospels and Acts 

The Gospels employ these terms in their basic meaning, i.e. ‘serving at table’ more than any other NT writings.

Mark and Matthew

Mark and Matthew go parallel in several passages in this regard. In Mk 1.13 Jesus is in the wilderness waited on (diakoneô) by angels; in the parallel  Mt 4.11 the angels wait on Jesus after the temptation. [Lk does not mention this feature.] After being healed by Jesus, Peter’s mother in law serves (diakoneô) her healer and guests ( Mk 1.31; Mt 8.15; Lk 4.39). Both Mark (15.41) and Matthew (27.55) tell us about the women who had served / provided for (diakoneô) Jesus, watching the crucifixion from afar. Luke (8.3) mentions these women’s service to Jesus in another context.
Matthew , on his own, has two other uses of the terms, he uses diakonos  for the attendants in the parable of The Wedding Garment (Mt 22.13) and in the Judgment Scene, he uses the verb diakoneô for the basic action of the true disciple,  “Lord, when was it that we saw you hungry or thirsty or a stranger or naked or sick or in prison, and did not take care of (diakoneô) you?” (25.44)

In the Gospels the concept of service is reversed by Jesus.
Mark’s Jesus takes up the ‘servant’ concept, reverses it and forms a christological concept regarding the nature and purpose of his life and that of his disciples. In Mk  9:35 Jesus tells the twelve  "Whoever wants to be first must be last of all and servant (diakonos) of all." In contrast to the rulers of the Gentiles this is repeated in Mk  10:43,   “But it is not so among you; but whoever wishes to become great among you must be your servant (diakonos),...” He further re-enforces this reversal, those who aspire to priority or greatness must be not just the ‘servants’ but even the ‘slaves’ of all (v.44). Then in  v.45 Jesus presents himself as the example and adds the christological notion of atonement,  “For the Son of Man came not to be served but to serve (diakoneô twice), and to give his life a ransom for many."

Matthew follows the same line as Mark in the reversal theme  in Mt. 20:26-28 and 23.11.  

Luke in  22:25-27  deals with the same theme of reversal but removes the notion of atonement in agreement with his christology in which atonement does not figure either in the gospel or in Acts. [The words at the last supper speech, 22.19b, 20, referring to  “the new covenant in my blood”, found in some mss, is not considered original.]

John

John uses the idea of service for the true disciple, “Whoever serves (diakoneô ) me must follow me, and where I am, there will my servant (diakonos) be also. Whoever serves (diakoneô ) me, the Father will honor.” (Jn. 12:26) However in his speech after the washing of the feet Jesus uses ‘slave’ not ‘servant’ terminology to explain his action (Jn 13.16). 
In the primary meaning, - service at table or domestic work, - this vocabulary  is  used  for the ‘waiters’ in the wedding story at Cana (Jn 2.5,9) and also describes Martha’s chores (Jn 12.2).

Luke /Acts  

The author of Luke-Acts in the gospel has, apart from those mentioned above, a few more instances of the ‘service’ terminology than the other evangelists.
The parable of The Waiting Slaves, containing innuendoes of the Messianic banquet, presents an unexpected and unlikely reversal as the shock ending - the master waits on his slaves,  “Blessed are those slaves whom the master finds alert when he comes; truly I tell you, he will fasten his belt and have them sit down to eat, and he will come and serve (diakoneô) them. (Lk. 12:37)
On the other hand, the parable of The Slave Returning from the Field, a situation more true to life than the preceding, actually its opposite, has the tired slave returning from the field, constrained to  cook for and serve (diakoneô) his master (Lk 17.8). The shock element here is in v. 10, the disciples, as unworthy slaves, have to do their duty.
In Luke we also have Martha’s domestic tasks,   “But Martha was distracted by her many tasks (diakonia); so she came to him and asked, ‘Lord, do you not care that my sister has left me to do all the work (diakoneô) by myself? Tell her then to help me.’”  (Lk. 10:40 )

Acts  
 First let us mention the two instances where diakonia  means provision of care or relief, a) “... the Hellenists complained against the Hebrews because their widows were being neglected in the daily distribution (diakonia).” (Acts 6:1) This complaint led the Envoys to ask the assembly to appoint seven men to take care of the  food service (6.2). The author is probably reflecting the conditions in his own times when the separation between the Jewish and Christian groups was well under way, since it is unlikely that in the thirties the widows and the poor of these messianic communities, as they were still Jewish, did not avail themselves of the help provided in the normal Jewish  manner, namely that the local poor were given money or provisions for one or more days, and the  transient paupers received daily offerings of food collected by certain helpers from house to house. Furthermore to argue, from this passage, for the institution of the ecclesiastical order of deacons goes beyond the evidence, the term diakonos not only does not occur here but it does not figure anywhere in the two volumes of Luke-Acts.
b)The other instance where diakonia is used of material help is Acts 11:29 referring to the relief sent by the community of Antioch to that of Judea.

In the rest of Acts diakonia denotes the work of evangelization. In the first speech of Peter to the early assembly, Acts has Peter referring to Judas’ position among the Twelve as “this service” (diakonia 1:17)  and in v.25  the term is coupled with ‘envoyship’ (episkopê). The work of the Envoy is termed in Acts 6:4, “the service (diakonia) of the word”  as distinguished from the “serving at tables” (6.2).
The task of Barnabas and Saul  to or from (there is a textual problem here) Jerusalem  is called diakonia (12:25). This seems to refer back to the work of Saul and Barnabas in 9.27ff.  
Paul, in his speech to the elders of Miletus uses diakonia for the task “that I received from the Lord Jesus, to testify to the good news of God's grace.” (20:24) and again the conversion of the Gentiles through Paul’s ‘service’
(21:19) .
In Acts 19:22 those helping Paul in his missionary work, i.e. Timothy and Erastus are so described by the verb diakoneô.

The Deuteropaulines 
In these writings the terms of our topic refer to the service of evangelization.  In  Ephesians the purpose of the gifts “that some should be envoys, some prophets, some evangelists, some shepherds and teachers” (4:11) is “to equip the saints for the work of service (diakonia), for building up the body of Christ,” (4.12) thus all the functions in the community are service for the edification of the whole community (‘the saints’). 
The author describes himself as a ‘servant’ (diakonos) of the Gospel (3:7)   “according to the gift of God's grace that was given me by the working of his power.”   In 6:21   Tychicus  is described as “a beloved brother and a faithful  assistant (diakonos) in the Lord.” Obviously this is meant as help in the work of evangelization not in material care.  

In Colossians Tychicus is again described in the same terms,  “a beloved brother, a faithful assistant (diakonos), and a fellow slave  in the Lord.” (Col. 4:7)  Other ‘helpers’ are mentioned in this writing: “Epaphras, our beloved fellow slave. He is a faithful assistant (diakonos) of Christ on your behalf,” (Col 1.7) and  Archippus is enjoined to, "See that you complete the task (diakonia) that you have received in the Lord." (Col. 4:17)
 As in Ephesians the author also calls himself a diakonos  ‘of this Gospel’ (1.23) and he, “became its servant (diakonos) according to God's commission that was given to me for you, to make the word of God fully known.” (1.25) 
 

The Pastorals 
A possible reference to the material help rendered by an individual in these writings is 2Tim 1.18. The nature of Onesiphorus’ service (diakoneô) in Ephesus  is not clear as to whether it was material help or evangelical help, however, v. 16, “he often refreshed me, he was not ashamed of my chains” i.e. relief of the hardships of imprisonment,  points more to the former. 
The reference to Mark in 2Tim. 4:11 is also unclear.  “Only Luke is with me. Get Mark and bring him with you, for he is useful in my service (diakonia).” This could mean either for personal service in prison or for ‘my task’ as an evangelist. However in other writings, if one may use one writing to explain another, Mark is known as a helper of Paul in the gospel preaching (cf. Col 4.10f - “my fellow workers for the kingdom of God.”)

Paul’s or the author’s task, similar to the authentic Paulines, is termed  a ‘service’ (diakonia) to which he was appointed by Christ (1Tim. 1:12)  and Timothy, the addressee, in as much as he instructs the brethren is called “good servant (diakonos) of Christ Jesus” (1Tim. 4:6 ). Again in 2Tim. 4:5  Timothy’s work as an evangelist is called diakonia. 

1 Timothy, more than other writings,  deals with service in the communities; here we find the qualities desired in the functionaries of the community.
In 1Tim 3, after the author lists several characteristics required of the overseers (episkopos),  in v.8ff he also lists the requirements of the assistants (diakonos), both male and female. [v. 8] “Assistants (diakonos) likewise must be serious, not double tongued, not addicted to much wine,  not greedy for gain; [9] they must hold the mystery of the faith with a clear conscience. [10] And let them also be tested first; then if they prove themselves blameless let them serve (diakoneô).” Regarding the female assistants he writes, [11] “The women likewise must be serious,  no slanderers, but temperate, faithful in all things.” From the context and from the parallelism between the qualities required for them and for the male assistants, these must be female assistants not wives of the male assistants. (cf. Rom 16.1 Phoebe a female assistant, diakonos.) In v.12 the writer returns to the male assistant to add the same requirement of the overseer in view, perhaps, of the probability that male assistants become overseers. [v.12] “Let assistants (diakonos) be the husband of one wife, and let them manage their children and their households well;” (compare vv.2,4). V.13 is general, for all assistants, “for those who  do the service (diakoneô) well gain a good standing for themselves and also great confidence in the faith which is in Christ Jesus.” 

The group of widows within the community dealt with in 5.3-16 may belong in the topic of service. After some instructions relating to the real widow, i.e. who is all alone (vv.3-8), the author sets down some regulations regarding the enrollment of widows. The purpose of this enrollment is not clear,  but the fact that these regulations, obviously not conditions to receive support,  are reminiscent of those regarding the overseers and assistants, this group must have had certain duties within the community albeit such duties are not disclosed. [v. 9] “Let a widow be enrolled if she is not less than sixty years of age, having been the wife of one husband; [10] and she must be well attested for her good deeds, as one who has brought up children, shown hospitality, washed the feet of the saints, relieved the afflicted, and devoted herself to doing good in every way. [11] But refuse to enroll younger widows; for when they grow wanton against Christ they desire to marry, [12] and so they incur condemnation for having violated their first pledge. [13] Besides that, they learn to be idlers, gadding about from house to house, and not only idlers but gossips and busybodies, saying what they should not. [14] So I would have younger widows marry, bear children, rule their households, and give the enemy no occasion to revile us.” 

Other Writings 

In 1 Peter only the verb (diakoneô) is employed. Exhorting his readers to love one another and practice hospitality to one another, the writer encourages them to be good stewards of the bounty of God by serving (diakoneô) each other with the gifts received, (4.10) and details two gifts, that of speaking and that of serving, “Whoever speaks must do so as one speaking the very words of God; whoever serves (diakoneô) must do so with the strength that God supplies, so that God may be glorified in all things through Jesus Christ.” (4.11)
In 1Pet. 1:12  the writer, in a general sense, uses the verb of the prophets who had things revealed to them, “(the prophets) were serving (diakoneô) not themselves but you, in regard to the things that have now been announced to you through those who brought you good news by the Holy Spirit sent from heaven-- things into which angels long to look!” 

 In one of his exhortations the author of Hebrews assures his addressees, who only here are called ‘beloved,’ that their work of relief on behalf of fellow christians are not unnoticed by God,    “For God is not unjust; he will not overlook your work and the love that you showed for his sake in serving (diakoneô) the saints, as you still do.” (Heb. 6:10)
In  1:14  this author says that all angels are “ministering spirits  sent into service (diakonia) for the sake of those who are to inherit salvation.” 

In Revelation diakonia is listed with love, faith and endurance.  The words of the Son of God to the angel of Thyatira start  with the good actions performed before they proceed with the censure,   “I know your works-- your love, faith, service (diakonia), and patient endurance. I know that your last works are greater than the first.” (2:19 )

This overall picture of the uses of this wordgroup leads to the conclusion that it is hard to envision the institution, by Jesus or the ‘Apostles’,  or even the existence of the ecclesiastical order of the diaconate in the first century of the common era.