Here's another good post worth quoting from FreeRepublic (from Tantumergo):
"But even if it's true does it necessarily mean God doesn't exist or He isn't the God we've all been sure he was?"
No, it doesn't mean that, even though it is a theory concocted and promoted by atheists in order to provide a materialist explanation for the existence of life.
However, whether it is true or not as a scientific theory is of great importance, because it fundamentally affects the paradigm or worldview within which people operate. Not least, from the moral perspective, if you keep telling people for long enough that they are simply monkeys with big brains, then we should not be surprised if they eventually start acting like monkeys with big brains, and before you know it you will have a world filled with Hillary Clintons!!!
It has also been the bane of Catholic theology for the last 70 years. Once "theologians" such as Pierre Teilhard de Chardin SJ got it into their heads that evolutionism was the way that the world worked then modernism received a massive boost. No longer was the deposit of faith something that had been delivered once to the saints in a world of fixed and immutable truth, but now everything was involved in a process of development - a process of becoming rather than being. Everything that had gone before could be discarded or re-interpreted to fit with a process of updating and adaptation to the world in which we lived. All history was caught up in an evolutionary flow of progress of the advancement of man, headed towards that point in the future where mankind would evolve into the cosmic Christ. Teilhard de Chardin was roundly condemned by Pius XII, but the Jesuits are still trying to rehabilitate him to this day.
The theory has also been used very effectively by heretical theologians to undermine the doctrine of Original Sin and consequently the need of mankind for a Redeemer.
Obviously Genesis is not meant to be a science textbook which gives detailed how-to's of the creation. God could have created by a process of evolution if he had wanted to, however, he gives us no indication in Revelation that He did and there is no evidence from science that he did either.