Foundations
Morality 101
A basic guide to the foundations of Catholic morality.
God is Love.1 John 4:8
The single most important concept for our morality is that "God is Love", from 1 John 4:8. Even though this statement is so simple, it has far reaching implications that shape how we think and act. In fact this explains why we need God: think about where our lives would be without Love, how miserable human existence would be. This is fundamentally why we have morality: without it, we would lose our way and lose the true meaning of love. Because we, as humans, are far from perfect, we can't always fully understand how to love ourselves and others properly, which is why we need morality from God to help us in this area.
It is from this idea, that God is love, that Jesus draws the two commandments he gives in Matthew 22:37-40: to love God and to love neighbor. Every sin that we commit either fails to love God properly or to love neighbor properly. We see this structure in the 10 Commandments that the examination of conscience is based on: the first 3 commandments are about properly loving God, while the other 7 are about properly loving neighbor.
Often times it is easy to view morality as a restraint, something that keeps us locked in and prevents us from having fun. The analogy of a dog on a leash helps us understand what's truly happening: when a dog is just roaming outside, it is full of excitement and wants to do all sorts of things, go anywhere it wants. But, as humans, we recognize all the dangers in the world to our beloved dogs (cars, getting lost), and so we keep them on a leash: not because we don't want them to have fun, but because we care deeply about them and want them to be safe. So too with God: God loves us more than we could ever know, and so He gives us morality so that we can stay close to Him and avoid the danger from sin, which can be hard to recognize on our own.
But, instead of keeping us on a leash, God has given us free will. This is why morality is often phrased in the form: "You shall not …" or "Don't do this". There is so much that we can do to love others, that it is far more practical to outline the common ways in which we fail to love than to describe the countless ways that we can love. Fortunately, Jesus is also the Good Shepherd, always ready to take us back into his arms when we need Him. Just like a baby runs back to his/her parents when he/she gets scared, so too do we need to run back to Jesus when we recognize that we have sinned, most especially in the Sacrament of Confession.