Has it really been such an excellent moral framework? You are immersed in a christian moral system, and then judging christianity according to that same system. A different society might prioritize things like strength, honor, discipline, self-mastery....etc. By that metric, a christian is a moral failure.
Much of christian morality does not even come from the bible, rather it's just slave-morality used to keep a docile population. Christianity was introduced by Constantine as a replacement for Sol Invictus, a unified Roman diety that was intended to give the emperor an aura of invincibility, and reduce the number of rebellions and secure his rule. Throughout history Christianity has been employed by the king as a means to secure his rule. It was so important that these kings set about stamping out any other religious traditions within their domains, without remorse.
In fact if Christians actually took their morals from the bible they'd be sacrificing goats and smearing blood on the walls, and genociding the enemies of the Chosen. Some christians actually do read the bible, and do dip their toes into that stuff.