I am listening to John Chapter 20, and was wondering what Mary Magdalene's history of prostitution is based on?
There is no biblical support for the view that Mary Magdalene was a prostitute. The story originated from a Catholic pope centuries after the scriptures were written, who supposed that the prostitute mentioned in Luke 7:36-50 was Mary Magdalene, but there is no support in the text for such an assumption. In fact, there is more reason to discredit the theory than to support it.
Pastor Armstrong mentioned Mary had a “history of prostitution” referring to the historical view that Mary was a prostitute. He was not confirming she was a prostitute, but rather he was acknowledging that she is widely considered to be a prostitute by history.