William Lane Craig has given an extended defence of the following version of the Cosmological Argument for the existence of God:

Since everything that begins to exist has a cause of its existence, and since the universe began to exist, we conclude, therefore, that the universe has a cause of its existence. We ought to ponder long and hard over this truly remarkable conclusion, for it means that transcending the entire universe there exists a cause which brought the universe into being ex nihilo ... we may plausibly argue that the cause of the universe is a personal being.

This ‘Kalam’ version of the Cosmological Argument may be laid out formally as follows:

(i) The universe began to exist.

(ii) Everything which begins to exist has a cause. (The Causal Principle.)

(iii) Therefore the universe had a cause.