Why was Newton a theist?

[Amarok]

Lemaitre ! Sure, but his knowledge was gained by the scientific method not his religious studies. Religion is not a method for gaining knowledge about physical reality.

And he would've strongly agreed with you on this.

By 1951, Pope Pius XII declared that Lemaître's theory provided a scientific validation for Catholicism. However, Lemaître resented the Pope's proclamation, stating that the theory was neutral and there was neither a connection nor a contradiction between his religion and his theory.[20][21] When Lemaître and Daniel O'Connell, the Pope's science advisor, tried to persuade the Pope not to mention Creationism publicly anymore, the Pope agreed. He persuaded the Pope to stop making proclamations about cosmology.[22] While a devout Roman Catholic, he was against mixing science with religion,[23] though he also was of the opinion that these two fields of human experience were not in conflict.[24]

https://en.wikipedia.org/wiki/Georges_Lema%C3%AEtre

I will also point out anyone at that period could have discovered it if they were looking .