... then how do you know that Jesus really said "Upon this rock I will build my church"? Maybe they misheard Him. Maybe He meant it in some vague allegorical way, and didn't at all mean it the way Roman Catholicism claims He meant it. Maybe the Gospel writer ad-libbed it and it was never said.
Point is, if you don't believe the Genesis account of Creation, then why would you believe anything else that is said in the Bible and that INCLUDES all the other statements like "upon this rock" and "the keys to the kingdom" etc, by which the Roman Catholic Church demands subservience to it.
What you are trying to do is set up a faux contradiction.
Science isn't faith and vice versa. There is a huge difference between accepting the 10 commandments as being an authentic way to deal with living a good life and has having come from God through Moses and trying to set up bugaboos that have more to do with the empiracle innocence of that time and the necessity of giving simpler explanations.
You need some sort of teaching authority to interpret scriptures. The Jews had an oral tradition that went along with the Torah, and have developed many written traditions of varying authority as well.
The Theory of Evolution is not a point of Catholic doctrine. The Pope has said that Catholics may consider it, as long as they agree that all humanity is descended from a first couple, whom the Bible names Adam and Eve.
Personally, I think Darwin's General Theory of Evolution is a load of unscientific hogwash. But I don't believe that God probably created the universe around 4000 BC, because I find it hard to believe that He would have bothered to create all those fossils, ancient rocks, or a stellar universe that seems to require billions of years to produce the heavy elements--and faked the whole thing just to make fun of modern scientists.
Parts of the Bible are literal, parts are metaphorical, and parts are arguable as to which they are. I believe in the historical existence of Abraham, Isaac, Jacob, and Moses. But it doesn't really matter, for the essentials of the faith, whether or not Job was a real man, or a figure in an extended parable told to illustrate a point. In the same way Jesus' story of the Good Samaritan doesn't depend on whether such a person ever existed. I reserve judgment on Job's historical existence, but not on the moral and spiritual lesson the book teaches. I believe in the actuality of Moses, because I believe that a real, living God acted in history, not in fable, and therefore spoke to and through particular people.
I'll paraphrase Jesus: "If it is your eye that causes you to sin, pluck it out and cast it away. If it is your hand that causes you to sin, cut it off. For it is better to enter the Kingdom missing an eye or a hand than to be rejected whole."
If we followed all of the Bible literally, Christians would certainly be easy to identify, wouldn't we? Obviously Christ was using hyperbole to get his point across, that we should avoid the causes and near occasions of sin. He did this often. What do you think His parables were about, after all?
Taking the Bible literally and claiming it is the only outlet of the Word of God leads Christianity into an intellectual trap. Certain verses of Scripture clearly contradict each other if taken literally and no other knowledge of history and conventions of the time are taken into account. If it is all to be taken literally, and contradicts itself to the literal-minded reader, then it certainly loses its credibility real fast, doesn't it? This fact has been used to discredit Christianity, allowing secularism to take hold to the extent that it has.
As for the evolution and creation question, Catholics are free to consider whatever scientific explanation they wish, within reason. We do believe that man is descended from Adam and Eve. Some Catholics do believe that the earth is only a few thousand years old, and theorize that just as God created Adam as a grown man, He may well have created fossils for us to discover. Perhaps their purpose is that we are to satisfy our intellectual curiosity trying to find their origins.