What does Romans 1:24 mean?
Paul has been describing human unrighteousness as a progression, showing how rejecting one aspect of God leads to ever greater rejections of Him. In spite of the fact that God has made his existence and basic qualities obvious through what He has made in creation, humanity in our sinfulness refuses to see Him there (Romans 1:18–20). Because we hide our eyes to the truth of Him, we do not honor and worship Him as God. Since we have rejected Him as God, we do not give Him thanks for all He provides.Because we have rejected the truth that He is creator, provider, and Lord over all, we cannot come to any right conclusions about how the universe works. The result is that our thinking becomes worthless, and our hearts grow dark to even the possibility of the one, true God. Still, we long to worship something and so create images made to look like people and animals. We foolishly worship our images, thinking that we have become quite wise (Romans 1:22–23).
Now Paul describes God's response. This, interestingly, involves God "stepping away," in a sense. In His great anger, God gives humanity over to our animal urges. The idea seems to be this: If we are willing to worship images of animals, God will allow us to live like animals in our relationships with each other. This particularly applies to issues such as sex, but the deeper meaning applies to all of our behaviors. God's design for sex between a man and woman in marriage, established even before sin entered the world (Genesis 2:23–25), is a great and beautiful gift. In response to human idolatry, God specifically gives humanity over to the full indulgence in the corruption of this gift.
This may not sound like much of a punishment, at first. On closer inspection, though, we should consider the amount of human misery resulting from unchecked expression of human sexual desire, in all of its corrupted forms. The consequences of God stepping aside and letting us reap the natural results of our own foolish choices with respect to sex, is impossible to overstate.