The Kalam Cosmological Argument for the existence of God

In a previous post I suggested that my atheistic colleague at Porkopolis consider the Kalam Cosmological Argument for the existence of God. Before I tackle his reply, it would be wise for me to outline what the argument is.

The Kalam Cosmological Argument

1. Whatever begins to exist has a cause of its existence.
2. The universe began to exist.

2.1 Argument based on the impossibility of an actual infinite.

2.11 An actual infinite cannot exist.
2.12 An infinite temporal regress of events is an actual infinite.
2.13 Therefore, an infinite temporal regress of events cannot exist.

2.2 Argument based on the impossibility of the formation of an actual infinite by successive addition.

2.21 A collection formed by successive addition cannot be actually infinite.
2.22 The temporal series of past events is a collection formed by successive addition.
2.23 Therefore, the temporal series of past events cannot be actually infinite.

3. Therefore, the universe has a cause of its existence.

-- William Lane Craig

Ta-da! I'll post a reply to Porkopolis' objection soon.