There's a difference between true and literally true. Most denominations teach that the truth in Genesis is that God created everything but humans created a separation between us and God (the Fall). That does not require the literal creation or a world-wide flood to be true.
Well, if you don't believe in Noah and his boat, then you're not a Christian. You can think you are, but you'd be wrong. You can even make up a new religion (denomination), but you'd still not be a real Christian, just a faker.
You do realize that neither the Catholic, Orthodox nor most mainstream Protestant churches require or advocate a literal reading of Genesis? Lot of people you're saying aren't Christians. What is your authority to define Christianity again? I missed it.
But let's look. You must have missed it earlier in this thread when I posted it:
Genesis 30:37-41
37 And Jacob took him rods of green poplar, and of the hazel and chesnut tree; and pilled white strakes in them, and made the white appear which was in the rods.
38 And he set the rods which he had pilled before the flocks in the gutters in the watering troughs when the flocks came to drink, that they should conceive when they came to drink.
39 And the flocks conceived before the rods, and brought forth cattle ringstraked, speckled, and spotted.
40 And Jacob did separate the lambs, and set the faces of the flocks toward the ringstraked, and all the brown in the flock of Laban; and he put his own flocks by themselves, and put them not unto Laban's cattle.
41 And it came to pass, whensoever the stronger cattle did conceive, that Jacob laid the rods before the eyes of the cattle in the gutters, that they might conceive among the rods.
But according to Evolution and Genetics, the rods would have no effect on the offspring.
So all we have to do is copy Jacob and see which prediction is correct: Will trees stripped of bark cause similar patterns as the Bible states, or will there be no effect as science states?
If you take the Bible literally, then that passage must be true with the specified cause and effect. And yet we know that will not work.
Next let's turn to our good friend Joshua.
10:12 Then spake Joshua to the LORD in the day when the LORD delivered up the Amorites before the children of Israel, and he said in the sight of Israel, Sun, stand thou still upon Gibeon; and thou, Moon, in the valley of Ajalon.
10:13 And the sun stood still, and the moon stayed, until the people had avenged themselves upon their enemies. Is not this written in the book of Jasher? So the sun stood still in the midst of heaven, and hasted not to go down about a whole day
and then in 2 Kings
20:8 And Hezekiah said unto Isaiah, What shall be the sign that the LORD will heal me, and that I shall go up into the house of the LORD the third day?
20:9 And Isaiah said, This sign shalt thou have of the LORD, that the LORD will do the thing that he hath spoken: shall the shadow go forward ten degrees, or go back ten degrees?
20:10 And Hezekiah answered, It is a light thing for the shadow to go down ten degrees: nay, but let the shadow return backward ten degrees.
20:11 And Isaiah the prophet cried unto the LORD: and he brought the shadow ten degrees backward, by which it had gone down in the dial of Ahaz.
But we now know that the sun does not move around the Earth as both those stories state.
So, unless you're one of the few geo-centrists (and yes, they still exist) then you cannot take those two stories literally.
And unless you're deluded beyond belief, you can't believe that offspring are affected by what their parents look at while breeding.