NOTES for Rom 13:8-14
One of the chief shortcomings of the law, and not only in the religious sphere, is that it is very extensive. In order not to break it, let alone fulfill it, one must know it well and constantly remember to observe it. And since the law contains God’s will for how we should live in this vast world, its scope is too great for weak human beings. Judging by the apostle Paul’s words, there is nothing surprising in this, because in the Creator’s design it was not the law that was meant to govern our life. Not the law, but the Lawgiver. It turns out that there is a perfectly understandable and reliable, though by no means simple, way to fulfill the law: to love one’s neighbor. This is precisely what the apostle Paul means when he writes to Christians that we live not under law but under grace, for love is a gift that God gives us freely and undeservedly.
And since love is the fulfillment of the law, its absence is a violation of the law, that is, sin. By its nature, sin is nothing other than a lack of love. This is important because it gives us a practical way to determine whether our actions are sinful or not.