Theism is a cluster of views. The first of which is that God exists. Others are that God has all the relevant omni-attributes, that He created the world, and that He communicates with and performs miracles on behalf of humans. There is one additional view that is often overlooked. It is that humans are obligated to worship God. Importantly, this issue of worship is of central importance to traditional theism. And it extends into pagan thought that predates Christianity. Take, for example Epicurus' deployment of the argument from evil: