To begin, let's consider a few assertions of the traditional materialistic worldview. Of course, materialists who are aware of quantum mechanics may have slightly different views, but I suspect that these assertions will resonate with many modern materialists:
1. The laws of physics state that miracles are impossible. For instance, Jesus could not have turned water into wine because that would have violated numerous physical laws (conservation of energy, conservation of mass, the 2nd law of thermodynamics, etc...)
2. Even if God exists, He could not be a God who intervenes in the natural world because he would have to violate the physical laws that he supposedly created.
3. Consciousness or subjective mental experiences are a collective property of brains (just as wetness is a collective property of water molecules). There is no such thing as a "mind" or "consciousness" separate from physical constituents.
4. The universe does not contain "hidden" or "unknowable" realities that are fundamentally inaccessible to science and reason.
There are of course other major components of a materialist worldview, but I think that most materialists would generally agree with these four statements. By the end of this essay I hope to show you that, if you believe quantum mechanics, assertions 1 and 2 and 4 are simply false. Statement 3 can still be retained, but only at an extremely high cost. Based on these statements, I think it is clear what motivated Danish physicist and father of quantum mechanics Niels Bohr to remark "Anyone who is not shocked by quantum mechanics has not understood it."