Part 6: Free Will
Aside from a lack of imagination, there would be no reason not to assume that we have free will.
We certainly feel like we have free will when it is thwarted; when we have to do things we don't want to do. We certainly act like we have free will because we make choices whenever we are allowed to. We act like other people have free will because we expect them to take responsibility for their actions.
The only reason to assume that we don't have free will is because we have a primitive religion with an supposedly omniscient God that really has the same perceptual limitations that we do. A more sophisticated religion has no trouble accommodating free will and omniscience.
Consider a sequence of events that represents the life of an individual. At each point that represents a decision, there will be a variety of different sequences that represent the repertoire of choices allowed by the circumstances of that decision point. The next point on each of those sequences that represents a decision will have its own repertoire of choices. Starting at each decision point there will be a fan of sequences, and free will allows us to choose one of them. (There are also decision points that are so deeply habitual that we don't really notice we made a decision.)
Going out along a sequence this can get very complicated as it includes every possibility. But there is no reason why an omniscient entity (who we will call a "Deus ex Machina" or DeM) can't be aware of all of them. That's what omniscience is all about.
I am going to assume that "God" has the quality of omniscience. You have the choice of believing in a god that is less perceptive than mine, but it would seem to me that if you wanted to believe in a god it makes sense for that god to have the best qualities that our imaginations can endow him (or her, or it) with. In any case the argument can easily be modified to cover a god that has inferior qualities.
We looked (in the manner of a DeM) at the fan of sequences that stretch into the future. We can also look backward at all the paths that connect the initial point to the various past points that might precede it in a sequence. Finally we can consider all the points in the life-sequence of anything that has a life-equivalent, like a pebble that gets worn down as it rolls down the bed of a river. If we combine all of those sequences for everything that has suffered, is suffering or will suffer any changes, we can call that the history of the universe.
A DeM with omniscience will perceive that history as something static. If we can imagine a DeM with that kind of perception, surely God, (if a God exists), must have at least a perception that extensive even if God may perceive other things that have no relationship to us or our universe.
However, that level of perception makes other powers irrelevant. Omnipotence, for instance, would be exhibited by making a change in the history of the universe.
But if a DeM already perceives everything that represents a possible event in that history there is no point in the DeM changing something in such a way that it results in something that, to the DeM, already exists. It is like rotating a perfect sphere: no matter how you hold it, it looks the same. No matter what a DeM might do to the history of the universe the DeM's perception of the history of the universe always remains the same; so there is no point in doing anything.
The effect that this has on the practice of religion is that if there is no point in a DeM (or God, if a God exists) doing anything to change the history of the universe that it perceives, there is no point in our doing anything in particular to try to manipulate the DeM (or God) into doing anything.
No acts of behavior like prayer or other ritual is going to manipulate the DeM (or God) to do anything that will change the history of the universe as perceived by the DeM (or God), because the DeM (or God) already perceives all those things that, to our limited perception, haven't happened yet. Being omniscient makes a God impervious to bribery or manipulation.
However, there are plenty of actions we can take that will have an effect on us. Some of them will significantly affect the particular life-sequence that we perceive. The trick for us is to use our scientific and religious models (or "theories") to figure out what actions to take that will be the most effective.
The best way we know to do that is to seriously apply the methods of science to the choices we make, i.e., to invent a real science of human behavior. In other words we must create a model of social and personal human behavior that is self-sustaining and beneficial. Whether we call that a "religion" or a "science" is irrelevant.