Prove by the way you live that you have repented of your sins and turned to God. ( Luke 3:8)
We learn from these verses that converted sinners will always give evidence of their conversion. We are told that Zacchaeus ‘stood before the Lord and said, “I will give half my wealth to the poor, Lord, and if I have cheated people on their taxes, I will give them back four times as much!”
Jesus responded, “Salvation has come to this home today, for this man has shown himself to be a true son of Abraham. For the Son of Man came to seek and save those who are lost.” There was reality in that speech; there was unmistakeable proof that Zacchaeus was a new creature. There was decision in that speech. Freely pardoned, and raised from death to life, Zacchaeus felt he could not begin too soon to show whose he was and whom he served.
He that desires to give proof that he is a believer should walk in the steps of Zacchaeus. Like him, let him thoroughly renounce the sins which most easily beset him; like him, let him follow the Christian graces which he has formerly most habitually neglected. In any case a believer should so live that all may know he is a believer: a faith that does not purify the heart and life is not faith at all; grace that cannot be seen, like light, and tasted, like salt, is not grace but hypocrisy. The man who professes to know Christ and trust him while he cleaves to sin and the world, is going down to hell with a lie in his right hand. The heart that has really tasted the grace of Christ will instinctively hate sin.