Christians are people who have recognised that God is not in their lives and so they have resolved to find out what the problem is.They discover that the sin in their lives is proving to be a barrier between them and God.
They see that this will result in permanent separation from God and usually, at this point, attempt to remove the sin themselves - which is impossible.
They then discover that there is a way forward and it is one which God has already done for them.
God the Son, Jesus, has died on a cross. He was without any sin and therefore this selfless act can 'buy back' our sin; the sacrifice was big enough to cover all sin for all time. He has taken the merited punishment on our behalf.
All the would-be Christian is required to do is to: admit the sin, repent it, thank Jesus for what He has done and invite Jesus into his/her life.
That person is now a Christian.
Living the Christian life? - Ah, well. That is another story and for another time.
