Citation needed. This is a total straw man argument.

Believe it or not, but it turns out studies on this actually exist.

Two U.S. M-Turk studies (Studies 1A and 1B, N = 429) and two large cross-national studies (Studies 2–3, N = 4,193), consistently show that disbelievers (vs. believers) are less inclined to endorse moral values that serve group cohesion (the binding moral foundations).

Specifically, disbelievers are less inclined than believers to endorse the binding moral foundations, and more inclined to engage in consequentialist moral reasoning. […] It seems plausible that the more constrained and consequentialist view of morality that is associated with disbelief may have contributed to the widespread reputation of atheists as immoral in nature.

Very interesting also that you’re showing the exact same behavior (i.e. consequentialist moral reasoning) in the remainder of your comment. This poses the question, if society were to evolve to consider rape, murder, and theft as excusable or even desirable behavior, would you go along with it?

As I am positive you know, quite a few things in Judeo-Christian scripture were considered “moral” in their time but are now viewed as unquestionably heinous.

What exactly are you referring to here? Slavery? Persecution of homosexuality and witchcraft? I’m sure I don’t need to tell you that the abolitionist movement was largely driven by Christians, while the other two causes were championed by atheists or non-Christians. I’ll leave my moral judgment of the latter aside so as not to unnecessarily inflame the discussion with reactionary rhetoric, but I will pose the question of whether in light of the rapidly declining birth rates in the west, homosexuality is a net good for society as a whole.