The Creation story puts Adam and Eve at anywhere from 6,000 to 10,000 years ago (particularly when we take into account the details about Adam's age and the age of those after him).
All of the scientific evidence points to the conclusion that homo sapiens have been around for some 200,000 years, this in stark contrast to the Garden of Eden story. Indeed, all the physical evidence supports evolution on every level whether biological, geological, or astronomical. The only rational conclusion is that the Adam and Eve story is, well, a story.
And this is the first problem: If it is just a story then there never was a singular event called "the fall of man" and therefore all this business of killing bulls or a virgin human sacrifice on a cross is entirely baseless.
The second problem is this: If we assume that the Garden/fall of man story is true, the conclusion that we draw is that the God of the Bible is not, in fact, very good at all. There is not one human being who would kick his/her toddler child out of the house for disobeying them (certainly not on a first offense!) or (if they had the power) alter that child's core being so that every one of her descendants would be born "in sin" and under a curse. This would be akin to a prisoner conceiving a child during a conjugal visit and then the powers that be taking steps to ensure that the child was raised in prison since the parent had committed an offense.
Moreover, the very nature of forgiveness is such that it does not require sacrifice. If your child steals from you, you don't tell them that they have to sacrifice Rover before they can be at peace with you. And if your neighbor offends you, you do not reconcile to them by allowing them to kill your infant son. Either you forgive or you don't.
The entire thing is not only irrational but if any one of us behaved in a similar fashion, we'd be imprisoned. And rightly so.
Therefore, on the one hand the physical universe screams that the Bible story is not true and on the other hand everything that we understand about the words "good" and "loving" scream that the Bible story cannot be the story of a loving God. How then can anyone actually believe this stuff?