It is ironic that the Christian concept is built around free will, but their description of an all knowing deity, excludes the concept of free will.
If a deity can know the future, then it is pre-determined. Our free will is merely an illusion and the Christian God is merely toying with us. The original sin concept is logically absurd.
Independant of religious explainations, it appears that free will is an illusion anyway. If we are merely very complex bags of chemical soup, then we will respond to input in a manner determined by the pre-existing state of those chemicals and physical laws that determine chemical interactions. Our illusionary perception of free will is merely a by-product of consciousness.
Complexity or chaos theory is no realm for free will. It merely makes it much more difficult or impossible to predict the outcome. I don't think anyone would equate their perception of free will with randomness.
If we don't actually have free will, how would this change our perspective on reality?
It wouldn't at all.