Faith and Philosophy somewhat recently (2002) published a critique of the kalam cosmological argument that I think is decisive. The paper is written by Christian philosopher Wes Morriston and is entitled, “Must the Beginning of the Universe Have a Personal Cause?“, by Wes Morriston.
Morriston grants that the universe had a beginning in time. However, he scrutinizes in detail the claim that the First Cause is timeless and that it timelessly creates time. Along the way, he clearly, methodically, and forcefully develops two main objections to the kalam argument: (1) there is no reason to believe that the universe had a cause, and (2) even if the universe did have a cause, there is no reason to believe that cause is a person. I especially liked Morriston’s paper because he deflated Craig’s slogans (e.g., “out of nothing, nothing comes”) and he showed that nontheists who reject a caused universe are not violating any widely shared metaphysical intuition.
Overall, I would have to say that Morriston’s refutation of the kalam argument is one of the best, if not the best, I have ever read. Craig wrote a reply, which was then followed by Morriston’s counter-reply. From now on, whenever someone advances the kalam argument, I intend to simply refer them to Morriston’s excellent paper. (An added plus of Morriston’s paper is that I think it could be accessible to almost anyone, even laymen, with a little effort.) Anyone who is interested in the kalam argument but who has not read Morriston’s paper should do so quickly!