Why cannot God have free will and "dictate" (and thereby predict) the future? (The situation becomes different when multiple entities possess free will.)
Depends on your definition of God. If it includes perfect and omniscient, then that being can't make any decisions. They've already been made for him / her. That god is an automaton.
Or alternatively, s/he has "already" made all decisions outside of time/at the moment time began. From this point of view, any being that is both omniscient and omnipotent cannot change his/her mind, if said being changes over time, this implies s/he will make decisions now based on how s/he will feel about things later, after taking her/his own evolution into account.
I'm sure we're not saying anything that hasn't been said literally millions of times before half-drunk at countless frat parties.
> From this point of view, any being that is both omniscient and omnipotent cannot change his/her mind, if said being changes over time, this implies s/he will make decisions now based on how s/he will feel about things later, after taking her/his own evolution into account.
You see, the problem is that people think of the evolution of an omniscient deity as a strict linear progression from cause to effect, but actually it's more like a great big ball of wibbly-wobbly timey-wimey... stuff.