It absolutely blows my mind that anyone with a brain capable of independent thought cannot see how much Craig has introduced -- absolutely free of evidence or supposition of being axiomatic -- in proposition 4. These include: "uncaused", "personal," "Creator" (note the capital C, making it a proper noun), along with beginningless, changeless (the Bible itself refutes the "changeless" part, though Craig seems unable to remember that when its inconvenient), "immaterial," "timeless," "spaceless," "enormously powerful" and "intelligent." Not a single one of that long list of idiotic suppositions is implied in "If the universe has a cause of its existence."Agree that formally, the syllogism is valid if not sound, and that it is not an argument for God.
William Lane Craig uses the Kalam Cosmological argument, which appends a second syllogism (sort of) to introduce God into the argument:
1. “Whatever begins to exist has a cause of its existence.”
2. “The universe began to exist.”
3. “Therefore, the universe has a cause of its existence.”
4. “If the universe has a cause of its existence, then an uncaused, personal Creator of the universe exists, who sans creation is beginningless, changeless, immaterial, timeless, spaceless, and enormously powerful and intelligent.”
5. “Therefore, an uncaused, personal Creator of the universe exists, who sans creation is “beginningless,” changeless, immaterial, timeless, spaceless, and enormously powerful and intelligent.”
This argument, besides being a non sequitur, doesn't invoke his god.
It's a non sequitur because, as you undoubtedly know, the existence of a universe with a beginning doesn't imply a god, much less one so specifically defined. Why not a multiverse? Why not an uncaused universe with a beginning? Why not two gods?
And if that is the case, why even bother moving on to "5. Therefore...?" Only a fool could really be tempted to that.