Christianity is Dead, Long live the rEvolution!

[Fake Messiah]

Sure, Bow Before Zeus, evolution among other scientific discoveries (like genetics that also shows Noah and Adam never existed) did pretty much undermine Christianity - heck even Pope Pius XII admitted it in his encyclical Humani Generis where he wrote: "When, however, there is question of another conjectural opinion, namely polygenism [our descent from ancestors beyond Adam and Eve], the children of the Church by no means enjoy such liberty. For the faithful cannot embrace that opinion which maintains that either after Adam there existed on this earth true men who did not take their origin through natural generation from him as from the first parent of all, or that Adam represents a certain number of first parents. Now it is in no way apparent how such an opinion can be reconciled with that which the sources of revealed truth and the documents of the Teaching Authority of the Church propose with regard to original sin, which proceeds from a sin actually committed by an individual Adam and which, through generation, is passed on to all and is in everyone as his own."

So yes honest people did leave Christianity behind, while other simply deny science is right - and it is a mentality that they rather take their "facts" from authority (like Bible which they think was written by God) then just some men and women that observe world around us.
While the third kind of Christians (which seem to be in highest number?) simply decided that God is in another dimension: dimension of human imagination, so they just imagine what ever they want to gap differences between reality and fantasy and is actually a taboo topic for them.