1 Timothy 12-14 I thank him who has given me strength, Christ Jesus our Lord, because he judged me faithful, appointing me to his service, though formerly I was a blasphemer, persecutor, and insolent opponent. But I received mercy because I had acted ignorantly in unbelief, and the grace of our Lord overflowed for me with the faith and love that are in Christ Jesus.
In this passage, Paul is recognizing the limitations he had before he came to Christ. By most accounts, before his experience of being called by the Lord, Paul was not a great guy. Haughty and arrogant, Paul went around persecuting people that were following Jesus because he thought they had abandoned the true faith. (Side note: being cruel to someone is not the best method to get them to agree with you).
Then he had an experience, I think many of us would envy, where God spoke directly to him and said, “stop what you’re doing, come and join me.” Paul did a full 180 on life, he repented and started to do everything he could to spread the gospel of Jesus Christ. And though he started life as one of the worst of the worst, God still saw him as someone to be loved and someone who could be of use to the gospel.
I don’t think you’ve spent the first half of your life persecuting non-believers (if you are doing that please stop), but I’m sure there are things in your past that you’d rather no one remember. No matter what is in your past you have received the same mercy that Paul did. The grace of God is always available and never ending.
Jesus sees who you were, sees who you are, and sees who you will be, and in all those phases he loves you. If you are running from God, you only need to turn around to see him waiting for you, loving you, and willing to guide you back into the fold.
Every saint has a past, and every sinner can have a future. We just need to accept the grace and mercy that has been offered.