I wouldn't doubt it. But he was a heretic, not that there's anything wrong with that. I am too.
Well, if that is so, then I'm just glad for the excellent company.... :^)
Leibniz for one suspected Newton of pantheism. But I gather he just misunderstood what Newton was saying (in his Optiks and the Scholium Generale that he added to his masterwork Philosophiae Naturalis Principia Mathematica in 1713). It's pretty clear to me, though -- FWIW.
Leaning towards Deism, are we? Well. It's a start.