The Greek word used here for Lord is kurios, meaning - supreme in authority (from the Hebrew word Adonai; from Adon meaning - lord, master, owner).  There are many today who profess Jesus is Lord, yet "on that day" Jesus said He will say to them, "I never knew you; depart from Me, you who practice lawlessness."  These people cast out demons in His name and even perform miracles, but they do not do the will of the Father who is in heaven and they do not act upon Jesus' words.  Jesus is Lord IN their lives but He is not the Lord OF their life.

 

The word of God is very clear that salvation IS NOT making Jesus Lord.  Instead we learn that salvation is perceiving Him as Lord, perceiving Jesus as God.  In "Lord, I Want To Know You", a study on the names of God by Kay Arthur, Kay sums it up by saying, "We call Him Lord and rightly so - He is God.   Because He is God, He is Master, because He is God, He is Owner (He made me), because He is God, He is Lord."

 

Beloved, this is a hard but needed question, is Jesus Lord of your life or Lord in your life?  This question means the difference between eternal life and death.