Five tragic realities concerning the spiritual condition of lost people:
1. Lost people know that God exists (1:19-20)
2. Lost people suppress the truth of God in unrighteousness (1:18)
3. Lost people refuse to worship God or give thanks (1:21a)
4. Lost people become futile in their speculations (1:21b)
5. Lost people foolishly exchange the glory of the Creator for the worship of the creation (1:22-23)