Roman Empire cultural and intellectual elites pretty much all believed in some kind of infinite and perfect supreme being (or force or whatever). They saw the Greek and Roman gods as either fairy tales or else as manifestations or avatars or aspects of the supreme ground of being. Christianity partly succeeded because it was amenable to these kinds of philosophical concepts.Why? Greek and Roman gods were far from being perfect yet it didn't made them unpopular, polytheist religions don't have a perfect supreme being most of the time.
So a Christianity that rejects this philosophical version of God is a Christianity that is going to remain the religion of lower class people and foreigners. It won't take over the Roman world as in OTL.