But there is a universe now. Therefore there must be a first cause of the universe. Most organisms are not aware of acting for a purpose. There must be a superior being directing their purpose. The concept of a supreme being is of a being with all perfections.
Existence is a perfection.
The supreme being must exist. All three of the above arguments have been analyzed and criticized a great deal. They do show how human reasoning tries to grapple with the concept of a supreme being.