To take a very stark and very simple example. The Christian, in order to please the avatar of god that he worships, wilfully opposes evolutionary theory thinking that to do so pleases god. In actuality, evolutionary theory is part of the human story and is very much, through intent or causation, a representation of god. So the non-believer is acknowledging god and is close to god through learning about the human story but the believer, who has idolised one archaic avatar of god relevant to a now passed period of human understanding, is through his worship…not really paying reverence to god at all. If that makes some sense.
In this particular example, I actually agree that you are right, and Christians should accept evolutionary theory. After all, if God did not endorse evolutionary theory
in some form, why would he have put so much seeming evidence for it on earth? The critical part however, is to draw from this only what Descartes called clear and distinct conclusions, and nothing that is not fully justified by the "evidence."
More generally though, you have merely pointed out a possibility. We can never answer any questions about God definitively. So why worship a particular avatar? It can only be for the same reasons why we do anything. Although we can never really "know" anything, it does not matter so long as we are motivated to do things that serve a purpose, and belief / faith is a form of action. So simply, if it makes your life better, then believe; otherwise, do not. The question to examine is not whether God exists, or what form God takes, or what God wants of us, all of these questions are hopeless. The responsibility of the individual and community is to examine what is good for us and how we can better achieve what we want. Any faith in God must flow from this question, and more often than not it does in practice, despite that participants in the debate would claim otherwise.