belief precedes epistemology, choice precedes discussions of determinism

People had beliefs long before they started talking about epistemology and when the zombies come after the last human, long after the last philosopher has been killed, his last thought will be the highly accurate belief that he's about to become a zombie. There is no knowledge. There are only beliefs. (This does not mean that belief is arbitrary.)

What is worth discussing is methodology because some ways of forming beliefs are better than others. The ultimate goal, as with every human activity, should be happiness, or the avoidance of displeasure, or, however you put it, getting the most out of this life. Ideally, we'd all believe what we wanted to believe without regard to external realities, but self-deception tends to have costs even for oneself, and certainly for others. Intentional deception of others also has costs of course, and co-self-deception is an essential element of organized religion, nationalism, your various tribalisms. But by a broad definition, all social activity involves some degree of deception and an extreme commitment to truth will lead you to the nuttery, in part because there is no truth. In any case, some forms of deception are beneficial to society while others are not. 

It's been said that corporations aim to externalize costs and internalize profits. All institutions and selves rely on this same process as a matter of self-preservation. Good methods expose cost-externalizing deception, leading, in theory, to more people getting more out of life. 

Similarly, people were living by choosing because living is choosing, constantly, long before the question of freedom v. determinism arose and the above last human's last choice before he dies will not rest on the performance of the products of a philosopher's brain. 

How we think about the freedom v. determinism question can affect how we live, though, and this alone is what should matter. Think you're an alcoholic and you'll remain one. Think you can stop drinking and you can stop. Think the current human predicament is the best we can do and it probably will be. Think we can do better and increase our chances of doing better. All beliefs have effects because all beliefs are world, our beliefs about freedom v. determinism included.