The Impossibility of an Infinite Past

I've always been puzzled by the notion of the infinite past. But when I became a senior in my university studies, I came across a book by Stuart Hackett called the resurrection of theism. And so I thought at that time I have got to come to peace with this argument is this really a sound argument or not. Ever do a PhD in philosophy, I want to write on this subject and so that was what I did. Three books came out of that study; an argument that I have since defended in professional publications and debates over the years.