Sin is all the ways we rebel against God and resist his work in the world. However, sin is not ultimately rooted in our disobedience to a set of commandments. Sin is, at its root, the sign of a broken relationship. We were created to live in perfect harmony with God and our neighbor. Sin manifests itself in a wide array of broken relationships—with God, with our neighbor, and even with creation itself. In one way or another, sin is rooted in putting ourselves first, resulting in our inability to properly love God and our neighbor.
According to Scripture, the first man, Adam, was a representative man and had the capacity to either love and serve God as he was created to do, or to rebel against him. We might wonder why God gave such a choice to Adam. God could have created Adam without a free will. However, we all know even from our own experience with relationships that people with power and position can make us obey them, but cannot force us to love them. Love is one of the greatest capacities we have, but it is rooted in free will and choice. We have already demonstrated that God created us in his own image and desired that we have a relationship with him rooted in love. However, this cannot be possible unless we also have the freedom to go our own way, reject God, and pursue our own path. For love to be the nature of our relationship with God, it must be freely chosen.