Paul left a wide path of destruction as he went city to city persecuting God’s people, and yet in 1 Timothy 1:15, even as he names himself the foremost of sinners Jesus came to save, he can say that last part: Jesus came to save him. And He came to save us, too.
Most of us know what it’s like to mean every word of a commitment to God and then watch ourselves fail it just the same. Peter, the disciple who promised to die for Jesus and then denied him three times, knew that feeling better than anyone. John 21 is for all of us who find ourselves in that failed committer camp.
We can be inclined to delay approaching God, too busy obsessing on our doubts to come, much like Thomas in John 20. But Thomas _did_ come and so should we.