The last catechism answer showed us that sin is rejecting, ignoring, and rebelling against God, not treating God as God, and not giving him the honor that is his due. In the Bible, the most frequently described way that human beings do that is through the sin of idolatry. Idolatry is loving anything more than Jesus Christ. Idolatry is treating anything as more important than Jesus Christ for your meaning in life, for your happiness, for your security and hope, or for your self-regard. The reason why it’s so important to understand the sin of idolatry is that it can be growing in a part of your life for a long time and get very deep without it right away leading to clear, visible, and easily seen violations of God’s law.
So, for example, if affluence and your career have become too important to you, they’ve become idols, and that can lead you to working too hard and exhaustion. It can lead you to becoming ruthless. It can block the development of a loving heart and the fruit of the Spirit. It can thin out your relationships. It can hurt your family relationships. It can hurt your friendships. And all these things can be going on for a long time before it leads to a real overt example of lying or cheating or adultery, because idolatry can lead to those things.
So what’s important to grasp is this: sin is not just doing bad things. It’s turning good things into ultimate things, because it ruins your soul, destroys community, and dishonors God.