Paul answers our question: “And I thank Christ Jesus our Lord who has enabled me, because He counted me faithful, putting me into the ministry, although I was formerly a blasphemer, a persecutor, and an insolent man; but I obtained mercy because I did it ignorantly in unbelief” (1 Timothy 1:12-13). Paul was aggressively immoral and violent in his rejection of Jesus Christ. His story of sin and conversion is found in Acts chapters eight through nine.
God is great in love and mercy, even extending to people like Paul (formerly Saul). “And the grace of our Lord was exceedingly abundant, with faith and love which are in Christ Jesus.” (1 Timothy 1:14).
Our question is important because Paul says that it is the very reason He was saved! “This is a faithful saying and worthy of all acceptance, that Christ Jesus came into the world to save sinners, of whom I am chief. However, for this reason I obtained mercy, that in me first Jesus Christ might show all longsuffering, as a pattern to those who are going to believe on Him for everlasting life” (1 Timothy 1:15-16). Paul was saved to illustrate that God can save anyone who is willing to turn and be faithful. That includes you and me.
Praise God! “Now to the King eternal, immortal, invisible, to God who alone is wise, be honor and glory forever and ever. Amen.” (1 Timothy 1:17) You can change because you can be forgiven.