The biggest of sin is idol- worship, in other words, to worship things other than God. We should worship God alone. The knowledge about our Creator is the primary knowledge which we must attain. The knowledge of Jesus Christ is the true knowledge. God created man.
Many people make many gods for themselves.
As a result of such acts, they become sinners and are trapped in various evils, vices, and violations. People are conducting worship in other religions too. But they don't appear to worship the true God. They perform sacrifices and worship them, as they fear their evil works. To please their gods, some people sing invocations, bathe and clothe their idols and offer various offertories like coconut, fruit, food, liquor, fowls, goats etc., and engage prostitutes to dance before them.