OK, Wesker, let's say all that you've said was true, that Christianity is a fine belief system to run a society with, that it provides hope and warm fuzzies and makes dumb people pliant and harmless by giving them simple rules to follow and threats of Hell to keep them in line. That doesn't make Christianity true.
The worship of Amun-Re, Isis, Osiris, Ptah, Thoth, Neith, Nepthys, Hathor, and the rest created a stable society that lasted over four thousand years and created works of art and architecture that fill people with awe to this day. Compared to that, Christianity is still in short pants. Unlike the ancient Egyptian religion, Christianity has had a long series of bloody internecine conflicts between its sects (the sack of Byzantium by "fellow Christians" during the Crusades, the Thirty Years' War, the Troubles in Ireland, etc.). On that basis, shouldn't we all convert to the worship of the great Gods and Goddesses of the Two Lands?
Well, OK, converting everyone to the Egyptian religion might be a rather large project. Still, what you're suggesting here is that Christianity works as a Noble Lie to keep the rubes in line and order society by. Christianity is good not necessarily because it is an accurate description of reality, but because it's useful for things like providing hope and giving the simple-minded simple rules to live by.
"Religion is seen by the common people as true, by the wise as false, and by the rulers as useful." (Lucretius, I think...)