He was a Belgian
mathematician whose work on "the hypothesis on the primeval atom"
was to become The Big Bang Theory
He was a Jesuit priest. He was Monsignor Georges Henri Joseph Édouard Lemaître.
I am no follower of the Big Bang Theory not because of Lemaitre but because of the inherent flaws on the standard model of the theory.
So, the messenger is a theist.
I would like to know your thoughts on this.