When he rejects his Creator, he worships something in the materialistic realm. If you suppose that the age of idols is past, you are greatly mistaken. The Catholic church promotes image-worship in the whole world. Many bow before pot-bellied images of Buddha. Millions are devoted to a modern, moving, talking image in the corner of their living rooms.
Humanists worship themselves.
This rejection of God results in moral corruption. Therefore God also gave them up to uncleanness, in the lusts of their hearts, to dishonor their bodies among themselves, who exchanged the truth of God for the lie, and worshiped and served the creature rather than the Creator, who is blessed forever. For this reason God gave them up to vile passions. For even their women exchanged the natural use for what is against nature. These perversions are shameful and are harmful to those who engage in them.