This is a part of the Calvin's Institutes summary series post #3.
All men have an innate knowledge of God who is the Creator. Idolatry and atheism are two evidence for this. Idolatry: Men, who are by nature not humble to bow down and worship others, prefers to worship wood and stone than to have no God. Atheism: Those men who refuse to acknowledge God are so occupied in proving that there is no God in order to escape the thought of having God. Every single human being is ingrained in their minds with the conception and the due honour they owe to God the Creator.