I don't think Christianity and evolution necessarily are incompatible. IIRC we had a thread where we pretty much all came to a conclusion that evolution and Christianity are compatible--that evolution is a tool of creation.
My father being a revrend/ordained wedding minister believes this. It's important to note he represents the black sheep of his side of the family: the rest are highly religious regardless of their various individual political leanings. So conversations about this kind of thing with the rest of the family escalate to very nearly accusations of blasphemy.
As it stands... I suppose someone could call him/her own self a christian despite not believing in God. Deluded, wayward or lost. Intention and where their head is at is important. If they are unknowing about it, then they only need to learn.
This is an interesting (perhaps amusing) difference and at least people in this category are willing to admit it.
People who claim to believe in God but then forsake God and their beliefs in the way that they live at the least need some reconciling.
If they are consciously aware of this on the other hand, and think they're getting by with an exploit (Sin, repent, pass go and collect $200, repeat) then they are not being completely honest about themselves (I suspect someone else is unhappy as well, hint hint).
That drove me away from faith for a time. Something this disingenuous (as I believe Evil Q put it) is the workshop of the devil masquerading as an institution of God.
While critical thinking negated some things in the bible taken literally, nobody has provided me any evidence that the critical can't also be faithful in the absolute sense.