What is Faith?
All the passages below are taken from Charles H. Spurgeon’s book “All of Grace,” published in 1981 by Whitaker House.
By grace are ye saved through faith;
and that not of yourselves: it is the gift of God.
-Ephesians 2:8 KJV
What is this faith concerning which it is said, "By grace are ye saved through faith"? There are many descriptions of faith, but almost all the definitions I have heard have made me understand it less than I did before I heard them. Someone said that after he read the chapter, he would "confound" it. It is very likely that he did so, though he meant to expound it. We may explain faith until nobody understands it. I hope I will not be guilty of that fault. Faith is the simplest of all things; perhaps it is the more difficult to explain because of its simplicity.
Three Aspect of Faith
Faith is made up of three things: knowledge, belief, and trust. Knowledge comes first.
Knowledge
"How shall they believe in him of whom they have not heard?" (Romans 10:14 KJV). I need to be informed of a fact before I can possibly believe it. "Faith cometh by hearing" (v.17). We must first hear so that we may know what is to be believed. "They that know thy name will put their trust in thee" (Psalm 9:10 KJV). A measure of knowledge is essential to faith; hence the importance of acquiring knowledge. "Incline your ear, and come unto me: hear, and your soul shall live" (Isaiah 55:3 KJV). Such was the word of the ancient prophet, and it is still the word of the Gospel. Search the Scriptures and learn what the Holy Spirit teaches concerning Christ and His salvation. Seek to know God, "for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him" (Hebrews 11:6 KJV). May the Holy Spirit give you "the spirit of knowledge and of the fear of the LORD" (Isaiah 11:2 KJV)!
Know the Gospel. Know what the Good News is and how it talks of free forgiveness, change of heart, adoption into the family of God, and countless other blessings. Especially know Christ Jesus the Son of God, the Savior of men, united to us by His human nature and yet one with God. Thus He was able to act as Mediator between God and man. He was able to lay His hand on both and be the connecting link between the sinner and the Judge of all the earth. Endeavor to know more and more of Christ Jesus. Endeavor especially to know the doctrine of the sacrifice of Christ, for the main point that addresses saving faith itself is this: "God was in Christ, reconciling the world unto himself, not imputing their trespasses unto them" (2 Corinthians 5:19 KJV). Know that Jesus was "made a curse for us: for it is written, Cursed is every one that hangeth on a tree" (Galatians 3:13 KJV). Drink deep of the doctrine of the substitutionary work of Christ, for therein lies the sweetest possible comfort to the guilty sons of men, since the Lord "made him to be sin for us...that we might be made the righteousness of God in him" (2 Corinthians 5:21 KJV). Faith begins with knowledge.
Belief
The mind goes on to believe that these things are true. The soul believes that God is and that He hears the cries of sincere hearts. The soul believes that the Gospel is from God and that justification by faith is the grand truth that God has revealed in these last days by His Spirit more clearly than before. Then the heart believes that Jesus is verily and in truth our God and Savior, the Redeemer of men, the Prophet, Priest, and King of His people. All this is accepted as sure truth, not to be questioned. I pray that you may at once come to this. Firmly believe that "the blood of Jesus Christ his [God's] Son cleanseth us from all sin" (1 John 1:7 KJV). Believe that His sacrifice is complete and fully accepted by God on man's behalf, so that he who believes in Jesus is not condemned (John 3:17-18 KJV). Believe these truths as you believe any other statements, for the difference between ordinary faith and saving faith lies mainly in the subjects in which it is placed. Believe the witness of God just as you believe the testimony of your own father or friend. "If we receive the witness of men, the witness of God is greater" (1 John 5:9 KJV).
Trust
So far, you have made an advance toward faith; only one more ingredient is needed to complete it---trust. Commit yourself to the merciful God; rest your hope on the gracious Gospel. Trust your soul to the dying and living Savior; wash away your sins in the atoning blood; accept His perfect righteousness, and all will be well. Trust is the lifeblood of faith; there is no saving faith without it. The Puritans were accustomed to explaining faith by the word recumbency. It meant leaning upon a thing. Lean with all your weight upon Christ. An even better illustration is this: Fall at full length and lie upon the Rock of Ages. Cast yourself upon Jesus. Rest in Him. Commit yourself to Him. That done, you have exercised saving faith. Faith is not a blind thing, for faith begins with knowledge. It is not a speculative thing, for faith believes facts of which it is sure. It is not an impractical, dreamy thing, for faith trusts and stakes its destiny on the truth of revelation. That is one way of describing what faith is.
Faith Believes in the Person of Christ
Let me try again. Faith is believing that Christ is what He is said to be and that He will do what He has promised to do. Faith expects this of Him. The Scriptures speak of Jesus Christ as being God in human flesh, as being perfect in His character, as being made a sin offering on our behalf, and as bearing "our sins in his own body on the tree" (1 Peter 2:24 KJV). The Scripture speaks of Him as having finished transgression, made an end of sin, and brought in everlasting righteousness (Daniel 9:24 KJV).
The sacred records further tell us that He "rose again" (1 Corinthians 15:4 KJV) from the dead, and that He "ever liveth to make intercession for [us]" (Hebrews 7:25 KJV). The Scriptures also say that He has gone up into glory and has taken possession of heaven on behalf of His people. He will shortly come again "to judge the earth: with righteousness, shall he judge the world, and the people with equity" (Psalm 98:9 KJV). We are to believe most firmly that it is so, for this was the testimony of God the Father when He said, "This is my beloved Son: hear him" (Luke 9:35 KJV). This also is testified by God the Holy Spirit, for the Spirit has borne witness to Christ---in the inspired Word, by many miracles, and by His working in the hearts of men. We are to believe this testimony to be true.
Faith also believes that Christ will do what He has promised. Since He has promised to cast out none who come to Him (John 6:37), it is certain that He will not cast us out if we come to Him. Faith believes that since Jesus said, "The water that I shall give him shall be in him a well of water springing up into everlasting life" (John 4:14 KJV), it must be true. Faith believes that if we get this living water from Christ, it will abide in us and will well up within us in streams of holy life. Whatever Christ has promised to do, He will do, and we must believe this in order to look for pardon, justification, preservation, and eternal glory from His hands, since He has promised them to believers in Him.
Then comes the next necessary step. Jesus is what He is said to be. Jesus will do what He says He will do. Therefore, we must each trust Him, saying, "He will be to me what He says He is, and He will do to me what He has promised to do. I leave myself in the hands of Him who is appointed to save, so that He may save me. I rest on His promise that He will do even as He has said." This is saving faith, and he who has it has everlasting life. Whatever his dangers and difficulties, whatever his darkness and depression, whatever his infirmities and sins, he who believes thus on Christ Jesus is not condemned and will never come into condemnation.
May that explanation be of some service! I trust it may be used by the Spirit of God to direct you into immediate peace. "Be not afraid, only believe" (Mark 5:36 KJV). Trust, and be at rest.
Do Not Delay
My fear is that you will rest content with understanding what is to be done and yet never do it. The poorest real faith actually at work is better than the best ideal of it left in the region of speculation. The great matter is to believe on the Lord Jesus at once. Never mind distinctions and definitions. A hungry man eats even though he does not understand the composition of his food, the anatomy of his mouth, or the process of his digestion. He knows that he lives because he eats. Another far more clever person understands thoroughly the science of nutrition, but if he does not eat, he will die with all his knowledge. There are, no doubt, many in hell at this hour who understood the doctrine of faith but did not believe. On the other hand, not one who has trusted in the Lord Jesus has ever been cast out, though he may never have been able to intelligently define his faith. Oh, receive the Lord Jesus into your soul, and you will live forever! "He that believeth on the Son hath everlasting life" (John 3:36 KJV). [59-65]