Everyone experiences a certain amount of shame and regret over sins committed in their past. The Bible has much to say about shame and regret, and there are numerous examples of people in the Bible who experienced them.
Can you imagine the shame and regret Adam and Eve lived with after they spoiled by their sin the perfect creation God had made? They lived in a perfect world, had perfect minds and bodies, and had perfect close fellowship with God. But they were also given the freedom to make choices. When they chose to sin against God and disobey Him, it meant all of God’s creation was now subject to sin’s effects, which are disease, decay, death, and separation from God for eternity. And every human being afterward was born into this world with a sin nature—the natural inclination to sin. Thankfully, God is sovereign, and He had a plan even then to redeem His world through His Son Jesus Christ and give mankind a choice for salvation and eternal life with Him. But Adam and Eve must have lived out their lives on earth with much regret over the loss of the life they had with God before they sinned.
Another biblical example of shame and regret is the apostle Peter. John 13:37-38 describes the night of Christ’s betrayal. Right after the Passover meal, Peter tells Jesus that he would lay down his life for Him. Jesus responds by telling him that on that very night Peter would deny three times even knowing Him. Later that night, out of fear of losing his own life, Peter denied ever knowing Jesus (John 18:15-27; Matthew 26:31-35, 69-75). Yet this is the same Peter of whom Jesus prophetically said, “And I say to you that you are Peter and upon this rock (Peter’s surname, Cephas, means “rock”) I will build my church” (Matthew 16:18-19). After Peter’s denial of Christ that night, we see him go on and grow in his faith, eventually becoming one of the founding fathers of the early church in Jerusalem. He did indeed “strengthen his brothers” after turning back to Christ, as Jesus had foretold (Luke 22:32). While he must have lived with much shame and regret over his very public denial of Christ, his deepened understanding of the person and work of Christ overcame his emotions and feelings of failure. He realized that if Christ would not hold anything against him, neither should he hold anything against himself.
The Bible teaches us that once we confess our sins, accept Christ’s sacrifice for our sins on the cross on our behalf, and become children of God, we are cleansed from all our unrighteousness (Colossians 1:15-22), and our salvation is eternally secure (John 10:27-30; Hebrews 7:24-25). As we grow spiritually in our wisdom and understanding of God by spending time with Him daily in prayer and reading His Word, we find ourselves loving and trusting Him more and believing Him when He says that He has put our sin as far from Him as the east is from the west (Psalm 103:12). We find ourselves making wiser choices each day, sinning less, and not grieving the Holy Spirit with our actions (Ephesians 4:17-32). This is, and should be, the mark of spiritual growth in all believers in Jesus Christ.
Romans 8:1 is the quintessential verse that covers leftover feelings of shame and regret in the believer: “Therefore, there is now no condemnation for those who are in Christ Jesus.” So, once we have confessed our sins, both past and present, we needn’t continue to live in shame and regret over them. God has forgiven us and forgotten those sins, but often we have to remind ourselves of that fact in order to forgive ourselves and move forward in newness of life. “I have been crucified with Christ; and it is no longer I who live, but Christ lives in me; and the life which I now live in the flesh I live by faith in the Son of God, who loved me, and delivered Himself up for me” (Galatians 2:20).