Here’s the lecture, which was given in 2004 at the University of Colorado, Boulder. A very liberal university!

This lecture is suitable for intermediate and advanced Christian apologists.

The description of the video states:

This is quite simply one of the best lectures William Lane Craig (a philosopher of science) has given. Craig explores the origins of the universe. He argues for a beginning of the universe, while refuting scientific models like the Steady State Theory, the Oscillating Theory, Quantum Vacuum Fluctuation Model, Chaotic Inflationary Theory, Quantum Gravity Theory, String Theory, M-Theory and Cyclic Ekpyrotic Theory.

And here is the description of the lecture from Reasonable Faith:

A Templeton Foundation lecture at the University of Colorado, Boulder, laying out the case from contemporary cosmology for the beginning of the universe and its theological implications. Includes a lengthy Q & A period which features previous critics and debate opponents of Dr. Craig who were in attendance, including Michael Tooley, Victor Stenger, and Arnold Guminski.

Craig has previously debated Stenger and Tooley previously. And they both asked him questions in the Q&A time of this lecture. Imagine – having laid out your entire case to two people who have debated you before and who know your arguments well. What did they ask Craig, and how did he respond?

This lecture is based on a research paper published in an astrophysics journal, and was delivered to an audience of students and faculty, including atheist physicist Victor Stenger and prominent atheist philosopher Michael Tooley, at the University of Colorado at Boulder.

The whole research paper that the lecture is based on is posted online.