I appreciate this question greatly because it strikes so personally close to me and my family. I didn’t really want to tackle this here, but it is unavoidable. There are many ways to answer this. I admit I don’t know all the answers and I have chosen different beliefs at different times in my life. I know it will be extremely difficult to keep this short, but I will try.
The simplest answer, which is usually the best, is that the Bible story of creation is a parable used to teach us about spirituality and morality, not science. We know Jesus taught using parables all the time. He told stories that did not necessarily actually happen to make points about life, especially spirituality and morality. I believe Jesus was God, therefore, I know God teaches using parables. Thus it is logical that the story of creation in the Bible could be one of God’s parables.
Of course, the exact opposite is possible. The story of creation in the Bible could be exactly true, and the evidence for evolution could be completely false. There is a growing number of scientist who are concluding that the theory of Evolution simply can’t hold up to scientific scrutiny. Some who study DNA are finding it hard to believe that such a coding system could be created by chance or natural selection. The fact that DNA is a coding system at is a problem for atheist evolutionist. Science has erected huge “microphone” to listen in space for proof of intelligent life. They claim that any “code” or “language” is proof of intelligent life because code is only create by intelligent beings. Now we clearly of an extremely complex code found in even the simplest forms of life and we want to deny that it is a sign of intelligent design. I don’t think science can have it both ways. Others are looking at the time it appears to take for new species to appear and concluding that life as we know could not have evolved in the time since Earth’s formation. We cannot scoff at dissenters or dismiss them without consideration. Evolutionist who won’t consider the possibility they are mistaken are “religious extremist” with evolution as their religion. I’ve only been alive 50 years and I’ve seen science be completely wrong many times. I was taught we were headed for an ice age, and now they teach global warming, for example. There are atheist geologist who are starting to consider that maybe the great tetronic plate movements that we thought took many years only took a few years to occur and that they occured as little as 5,000 years ago. This would alter dramatically the age of fossils etc. , which would make the life as we know it on earth much “younger” than we now think.
Another possibility is that we are wrong about everything! We know that we humans have a long history of misinterpreting the Bible and scientific facts. Our track record on both is awful. I am perfectly willing to accept that someday God will open my mind and I will understand the Bible stories as he intended them to be understood and it will be totally different than how I now understand the English version I now muddle through. I have been taught humility. For example, I know the Hebrew word that is translated “day” can also mean “season of time”, which could change everything. And as stated above, science could also be wrong about the details of evolution, or even evolution in its entirety. Science (not the Bible) once taught that the sun revolved around the Earth. When God finally opens my mind to the truth it could be somewhere in the middle of, or something totally outside of, what we now even consider possible.
The last possibility I want to explore is that both the Bible and evolution are both correct. Many scholars have found ways of matching the Biblical text to evolution. I personally struggle with this and think they are twisting the text quite a bit, but it is possible. I will certainly grant that God could “create” things using evolution if he so chose.
So what is my final answer? First, you have asked a faulty question. Nothing is as obvious as you state. Evolution is not obviously true. It could be partially, or even entirely wrong. Your reading and interpretation of the Bible is also not obvious at all. The more I understand about physics, archeology, and the big bang theory, and the more I see science prove itself wrong over the years, I personally have chose to believe it happened just as the Bible says it did. But I also choose to admit I don’t know for sure and God may surprise me some day. I believe God is perfectly capable of somehow making it all work out and I don’t have to understand it totally. I’ve found enough of the Bible to be reliable, that I will not say it is wrong about anything. But I have also learned that at any one time my understanding of the Bible can be completely wrong. So I am left with saying I am only human, God is far greater than I, and I will trust him even if I don’t understand. Now an evolutionary scientist may smile at this and say his reasoning is superior to my faith, but I submit that an open minded person must admit that evolution has enough “holes” in it, that to believe it explains away the need for God requires far more blind faith than I am putting in God.