1 Timothy 1:13-17

13 Even though I was once a blasphemer and a persecutor and a violent man, I was shown mercy because I acted in ignorance and unbelief. 14 The grace of our Lord was poured out on me abundantly, along with the faith and love that are in Christ Jesus.

15 Here is a trustworthy saying that deserves full acceptance: Christ Jesus came into the world to save sinners—of whom I am the worst. 16 But for that very reason I was shown mercy so that in me, the worst of sinners, Christ Jesus might display his immense patience as an example for those who would believe in him and receive eternal life. 17 Now to the King eternal, immortal, invisible, the only God, be honor and glory for ever and ever. Amen.

(NIV)

This is a good passage to use if you want to share more of your personal testimony of coming to Jesus.

The point is a Christian is a bad person who has been rescued by a good God. After all, He saved YOU!