First, you must come to the conclusion that there is a God by whom you will be judged and to whom you must answer to. If you reject that notion, nothing I say can help you. I dare say that belief doesn’t make it true, the truth remains the same no matter if you believe it or not. Ultimately you will have to come to your own conclusion; but we do have a book in which the future was written before it happened and has, thus far, been 100% accurate.
Assuming you have to come to the conclusion that God exists and you will have to answer to him; you then have to realize that you have sinned against God and need salvation. The Bible states this fact. If, however, you do not believe you are beholden to anyone or any entity for your behavior, then the rest cannot happen. Romans 6:23 tells us that the “wages of sin is death;…” If that short version isn’t enough, we have the books of the Law. Read the consequences for pretty much any violation of the Law. Even without the written Law, everyone is born with a conscious. We know when something is wrong unless we have lead a life in such a way as to sear our conscious to uselessness.
So take a look at the Law. It can only condemn you. It only shows you how you have failed. Taken at just its most shallow meaning we still cannot uphold it all. All of those proclamations of capital punishment for even what seems minor sins has a reason. The wages of sin, any sin, no matter how small we think it is, is death. This is the purpose of the Law. Even if all you ever did in your entire life was lie once about some minor incident, you will suffer death. This seems harsh but I suspect it goes beyond our concept of human justice. We all agree there have to be rules for a society to exist. Sin is a corruption in the very being of a human – of creation even (all creation is cursed for the sin of Adam and man Romans 8:19-22) .
Now don’t think for a moment that God is some cosmic meany just waiting for you to do wrong so He can smack you down. Read Ezekiel 33:11 where God says He does not seek the death of the wicked but instead that they would turn to Him. The action, however, is yours to take. YOU must choose to turn away from your sinful life and come to Him.
Perhaps you don’t lie, not likely by maybe you don’t think you have. Perhaps you don’t covet, you don’t worship idols and other gods. Jesus explained the Law on an even deeper level. If you even think hatred toward your fellow human, you have already committed murder in your heart. Just looking after a woman lustfully (I suspect this applies to women looking at men as well) then you have committed adultery (and covetousness) in your heart.
So perhaps you have rightfully come to the conclusion that you are a sinner even on the smallest scale and that sin will cause you death. Not just of the body, that happens to everyone but this is a death on spiritual level. What do you do about it?
The short answer is you can’t do anything about it. Don’t dismay, however, God is not a cosmic meany, remember? He has a plan and has given one, Himself, as a redeemer for that sin.
God came down in the form of a man named Jesus. Long prophesied in the old testament. He came and lived the perfect life according to the Law. The only one in all of creation who could and did do this. He was then put to death, innocent of any guilt, thus paying the required price to cleanse all of us of our sin. What is more, he defeated death by rising again of his own accord. This isn’t just a fairy tale as modern society would have you believe. It is documented. Josephus wrote about it in the antiquities of the Jews. He was not a believer, at least not at the time he wrote his history texts. He had no reason to promote the resurrection. In this way, he was and is our kinsman redeemer. This is a concept also explained in the Old Testament; spelled out in Exodus and Leviticus and illustrated very well in the book of Ruth.
So that brings us back to the original question. What can you do about the sin nature that you have? I said. “nothing” and that is true, but the fact is, Jesus has done what you could not do. Because he lived and died and rose again you can be spared the death that is the inevitable result of a sin nature. Believe in him and you will have eternal life. That isn’t to say you will live here on earth forever, who would want to, but you will be raised again (should you not be of the final generation). That’s all you have to do. Believe in who Jesus is and what he did for you. Repent and be baptized in the spirit, said Peter.
Finally, if you are holding back because you think you aren’t good enough yet, keep in mind that Jesus died for you while you were still in sin (Romans 5:8). Accepting Jesus as your savior and Lord is not the end of the journey, it just the beginning.