When our Savior goes to work on us, his creative power that made the heavens, the earth, and all things also goes to work. He takes broken human beings, recreates them, and places his name on them through the water and the Word.
I find comfort in knowing that, like me, God loves to issue nicknames; some for endearment, others to make a stronger point. Jesus called James and John “the Sons of Thunder” after they wanted to call lightning down on some rude Samaritans. I imagine Jesus giggling a little at their sincere and yet misguided desire. Perhaps Jesus said, “Okay, Sons of Thunder, reel it in! We’re moving on to the next town.”
Jesus also takes Simon, a guy who seems to have a penchant for jumping out of boats and calls him “the Rock,” or Peter as you may know him. Peter properly confessed who Jesus is, and Jesus calls him a rock because of his rock-solid confession of Jesus being the Son of God, the Messiah. Once again, it may just be my weird sense of humor, but I like to think that it was not recorded that Jesus may have said, “you sure sink like a rock.” But we know that Simon is now called Peter by the Name above all names, so Peter’s confession of faith is ours. “Simon Peter replied, ‘You are the Christ, the Son of the living God.’ And Jesus answered him, ‘Blessed are you, Simon Bar-Jonah! For flesh and blood has not revealed this to you, but my Father who is in heaven. And I tell you, you are Peter, and on this rock, I will build my church, and the gates of hell shall not prevail against it” (Matt. 16:16-18). It only took Peter another five verses before he blew it, and Jesus called him Satan.
We have seen this renaming in the Old Testament. Abram becomes Abraham in Genesis 17. Jacob becomes Israel in Genesis 32. Renaming is nothing new for God.
Perhaps one of the most powerful renamings is when Saul of Tarsus, a man who persecuted Christ’s church, was laid flat by Jesus. After Saul saw the light, literally and figuratively, he received the name Paul.
I believe Paul received a new name for at least two reasons. First, I imagine that Paul had a conscience that was perhaps plagued by his behavior when he rejected Christ Jesus. It seems that he was presiding over the stoning of Stephen, the church’s first martyr. I know something like that would plague my memories for my whole life. So perhaps as a constant reminder, as Paul would later write,” If anyone is in Christ, he is a new creation. The old has passed away; behold, the new has come. All this is from God, who through Christ reconciled us to himself and gave us the ministry of reconciliation” (2 Cor. 5:17-18) So if Paul started to feel pangs of sorrow and guilt, Paul could declare to the accuser, “That was Saul; I’m Paul!”
I believe the other reason Paul received a new name is for the sake of the church that he persecuted. We know that the church distrusted him in the early days of his service to Christ. When accused by God’s Children, he could also proclaim, “That wasn’t me, it was Saul who persecuted the church; I’m Paul. I am a different person. God declared it so, and if the ‘I Am’ declares anything to be, it is.”
A new identity is a source of great comfort for the tender conscience and tender heart.
Many of us are plagued by embarrassing memories of our sinful pasts. We often pray with the Psalmist, “Remember not the sins of my youth or my transgressions; according to your steadfast love remember me, for the sake of your goodness, O Lord!” (Ps. 25:7). We pray that God would not remember them and count them against us. Still, we also pray that we would forget and not count them against ourselves.
When we fail to remember that Christ answered for all of our sins, when we live under accusation, we fall into the hands of the unholy trinity of the world, the devil, and our sinful self.
Martin Luther knew of this struggle as he famously said, “So when the devil throws your sins in your face and declares that you deserve death and hell, tell him this: “I admit that I deserve death and hell, what of it? For I know One who suffered and made satisfaction on my behalf. His name is Jesus Christ, Son of God, and where He is there, I shall also be!” 
Yes, I deserve every judgment, but my Jesus is greater than that unholy Trinity. He has defeated all of your evil accusations. To hell with you! We open the door to the fiery furnace of hell and yell, “In you go!” as we dump our guilt and the devil.
The only commandment that counts is the first; as Luther teaches us if we could keep that one, the others are of no consequence, for they are kept in the keeping of the first. Our God says, “You will have no other Gods before me.” Sometimes in hanging on to our useless guilt, we are idolaters. We believe our sin or conscience is more powerful than our God.
C.S. Lewis wrote, “If God forgives us, we must forgive ourselves. Otherwise, it’s like setting ourselves up as a higher tribunal than Him.” 
We are forgiven of every sin, past, present, and future, yet we often need to be reminded that God no longer remembers our sins; it’s time for us to put them away, take our eyes off of ourselves, and fix them on Jesus, the author, and finisher of our faith. He is the beginning, the middle, and the end, and our guilt has no place or power when we fix our eyes on his perfect love and grace for us.
Sin? What sin? Oh, you must have me confused for someone else; that wasn’t me, that was Saul; I’m Paul.
 Martin Luther, Letters of Spiritual Counsel, trans. and ed. Theodore G. Tappert (Vancouver, British Columbia: Regent College, 2003), 86–87
 C.S. Lewis, Collected Letters of C. S. Lewis