William Lane Craig a well-known philosopher and Christian theologian, as well as a historian and apologist. A professor at Talbot School of Theology and Houston Baptist University, Craig is perhaps best known for defending the Kalam cosmological argument, and for debates that are available on YouTube.
The cosmological argument is the idea that God's existence can be shown likely by appealing to known facts about how the universe works. The Kalam Cosmological Argument is a variation of that argument. Popularized by William Lane Craig, it addresses the question of the universe's beginning, and its logical cause.