That feeling is so painful, replaying that one sin in your mind over and over, beating yourself up for it, mentally, or even physically. Shame, it's a heavy burden to carry, and maybe you're carrying it. What causes this hurtful emotion and what can you do to kill it?
Let's take a hard look at why we feel shame. We sin and that thing inside us, the "c" word (our conscience), lets us know we sinned. So far, so good. We feel guilty because we know sinning is wrong, very wrong. We need to be punished for it. Still on the right track. But then, consciously or not, we throw away God's precious gift, deny HIS punishment in our place, and decide we can do it better. Our sin is too great for God's sacrifice, our own punishment is better. So we fall into shame, the carrying of our own sin, trying to atone in whatever way we can. Denying ourselves, giving to others, cleaning up our act, all right things done for the wrong reasons.
So if you dust it off and really take a look at it, shame is really pride, thinking we can save ourselves, how conceited is that? And that realization could drive us into feeling even worse. We not only carry shame, but now pride as well!? And no amount of good work is going to fix that because we already established trying to atone for our sin is the cause of the problem.
So that's shame, self righteousness. Now for the real question, how do we get rid of it?
The short answer? Lay it at the foot of the cross, along with all your other junk. Jesus can take it, He already paid for it.
The practical, everyday answer? Preach yourself the gospel every day, or whenever you catch yourself beating yourself up about the past. Stick a sword through it. Learn and move on. Trust God will use your sin and weakness for good, and for His glory. Memorize Scripture that assure you of God's gift and your freedom, or write them down on sticky notes and put them on your bathroom mirror.
Whatever you do, just kill it, and not by yourself, let God do it.
And you shall know the truth, and the truth shall make you free.” John 8:32
Therefore if the Son makes you free, you shall be free indeed. John 8:36
And I give them eternal life, and they shall never perish; neither shall anyone snatch them out of My hand. My Father, who has given them to Me, is greater than all; and no one is able to snatch them out of My Father’s hand. John 10:28-29
Being justified freely by His grace through the redemption that is in Christ Jesus, whom God set forth as a propitiation by His blood, through faith, to demonstrate His righteousness, because in His forbearance God had passed over the sins that were previously committed. Romans 3:24-25
For the law of the Spirit of life in Christ Jesus has made me free from the law of sin and death. Romans 8:2