As Christians continue to grow in holiness and the life of virtue, it is spiritually healthy to remember what exactly sin is so that we can better combat it. As human beings, we have been endowed with an intellect to know the good and a will to choose the good. Put another way, sin is a defect in virtue. Generally speaking, virtue is excellence in something. A virtuous painter is someone who paints well. A virtuous singer is someone who sings well, etc. A virtuous person is someone who knows the good and consistently chooses it. In biblical language, sin is referred to as "harmartia." This is a Greek term that was actually used in archery to signal if someone "missed the mark.”
So what do sins effects look like in our day-to-day lives? Sin darkens our intellect. Once we sin, it becomes easier to rationalize other sins that may follow. We might convince ourselves that if we've sinned once another sin might not be so bad. As long as it's not really hurting anyone it can't really be a sin. As long as no one knows about it, it shouldn't be sinful.
Sin also affects our will. It never happens by accident, and it is always a choice. Now of course, some of these actions might be worse than others depending on the situation and the gravity of the sin involved, like how murder is more sinful than a simple slap in the face, but both things would still be sin. It also affects our relationships with others. It leads to anger, distrust, fear, and sadness; but most importantly, it ruptures our relationship with God, and that is the worst result of all. God's very essence is goodness, there is no imperfection in him. God's essence is also existence, and not expecting any effect on our relationship with him would be like sitting on a tree branch, trying to cut it off of the tree, and not expecting to fall.
When I think about the consequences of my own sin, both big and small, I try to remind myself that God's mercy is such a great gift. His goodness is far more powerful than our own stupidity, and thank God for that. He never stops loving us. He is only waiting, waiting for us to reform our actions out of the harm that they've done both to others, ourselves, and him, and accept his forgiveness. He loves you. He wants you, and he will help you to “Go on your way and do not sin again” (John 8:11).
Another great article! The aspect of sin that darkens the intellect is most interesting to me. It's a real bind, just when you need your intellect to be sharp the very reason you need it has caused it to become useless, maybe even harmful to you. The intellect is so fallible even in the best of times, so when were in sin how can we navigate our way out? A terrible situation to be in, easy to see in others hard to spot in yourself.