Why We Sin

Have you ever truly pondered why we sin? I’ve been a Christian for nearly 30 years, but I sin all the time. Over the years, the reality of my sin before God has caused me a great deal of pain, frustration, and even despair. As a Christian, the overall desire of my heart is to please God; to be obedient to Him. And yet, I can fall into sin so easily. Sometimes, it has felt as though I were sinning against my own will.
In desperation, I would then cry out to God, asking why I struggle with sin as I do. I would ask pastors, Sunday School teachers, and other Christian friends. Or perhaps I would hear someone teaching on the subject. And the answer I’ve received most of the time is that it is caused by the Sin Nature. “You’ve got the Sin Nature inside you, compelling you to sin. It will be with you as long as you are on this earth, and there’s nothing you can do about it. The only thing you can do is fight against it as best you can. Do what you can to avoid sin, but understand that you will never be perfect in this life. You will always sin, at least on occasion. It just can’t be helped.”
This seems to be what I’ve always been taught, and I believe it to be true. However, I have a problem with using it as the default answer to the question as to why Christians struggle with sin—why I struggle with sin. I have a problem with it because it lends itself toward being just an excuse for sin. It allows for the potential of someone saying, when they sin, “Well, you know I just can’t help it. I’ve got the Sin Nature living in me.”
The truth is that, even though we do have the Sin Nature within us, it is never to be used as an excuse for sin. And I am not fully convinced that the Sin Nature by itself is a viable explanation for sin. Particularly since we also have the Holy Spirit living within us, empowering us to not sin. In addition, while the New Testament does acknowledge the reality of sin in the believer’s life (see I John 1:8, for example), the overall teaching of the New Testament is that a Christian is someone who no longer lives a sinful lifestyle. The Christian life is presented to us as a life of obedience to Christ.
So, regardless of how frequently or infrequently, why do Christians sin? Whenever a Christian commits any sin, how is it to be explained, without using the cliché that it’s just the Sin Nature?
I would submit to you two answers that I have received from a couple good friends of mine. And I will say that the second goes a long way in clarifying the first. In the midst of a discussion we had several months ago, one friend of mine told me that any time we sin, it reflects a wrong belief about God.
What he said rang true for me, but it also created a problem for me. What wrong belief do I have about God? I was raised in the church. I have studied the Bible as much as anyone else. I have even had a measure of formal biblical and theological training. I’ve got all my theological ducks lined up in a row. So what wrong belief about God do I hold to that causes me to sin?
This leads me to the answer given to me by another friend. In answer to the question of why I struggle with sin as I do, he said, “Jesus is not enough for you.” I instinctively balked at this statement, but only for a moment. For I quickly understood what he was saying. He was saying that whenever I sin, I have a need or a desire that I believe Jesus will not meet or fulfill.