Christians are interested in sin for the same reason that the Seahawks are interested in knees. Football players need to use their knees effectively in order to play well, but knees have inherent limitations. By studying how knees work and by proper exercises, we can improve the performance of our knees, but there are limits.
Our objective is eternal life with God, the source of all life. Sin cuts us off from God. By studying sin and by proper exercises, we can improve our performance, but there are limits. Here are some particulars:

The Creation of Adam – Michaelanelo
1. Sin can be thought of in terms of rules. God gave Adam and Eve one rule in the Garden of Eden (“Don’t eat that apple!”). God gave the Israelites the Ten Commandments at Mount Sinai. In each case, the rules proved too hard to keep. So sin can be thought of in terms of rules. But there is a deeper understanding.
2. Sin is part of our nature. Why did Adam and Eve fail to keep the one rule? Why did the Israelites fail to keep the Ten Commandments? What is it that prevents us from making it through even one day without slipping up on our best intentions? We seem to have some defect in our nature.
3. Sin separates us from God. Just as failing to keep a promise to your brother separates you from your brother, so failing to keep the commandments of God separates us from God. That is not good if our objective is eternal unity with God.
4. The root of sin is rebellion against God. The writer of Genesis understood this clearly. When the serpent tempts Eve, he says, “Eat the apple and you will be like God!” At root, our sin comes from rebellion against God because we really want to be in charge. A current billboard advises, “Thrive your way!” At a superficial level that is OK (like “enjoy yourself”), but at a deeper level the message is subversive. We want to thrive our own way, to set our own agendas, ignoring God. Imagine that the Seahawks show up at training camp and one says, “I have decided that I would like to photograph footballs this year, enough of this running around,” and another says, “I have decided to carry the ball into the stands every time I get it.” The coach would be perplexed: “Don’t you understand that our objective is to win games?” At root, sin comes from rejection of God, as if our half-baked plans were more important than his offer of eternal life.
5. The (partial) cure for sin is submission to God. Just as the Seahawks need to learn from their coach how their individual efforts can contribute to the overall team objective, we need to listen to God and learn how our efforts can contribute to our eternal life. This is best done together with other Christians. The more we can learn about and submit to God’s plans, the better off we will be.
6. The final cure for sin is Christ. No matter how hard we work, that defect in our nature will always be there. Even the most saintly people have recorded their frustration in being unable, by their own efforts, to achieve perfect alignment with God’s will. Jesus had to live and die for us because there was no other way to defeat sin. The time will come when we will all stand before Jesus and the question will be, “Do you love and follow me?” (This question would seem self-centered if anyone but the Lord were to ask it.) Let us begin training now to give the joyful answer, “Lord, I love you, help me to love you more!” That is the final cure for sin.