Determinism isn't religious. Also there is a big difference between the realization that everything happens for a future reason/purpose/goal and everything that happens is a sum of past events. I belong in the later field. Basically everything that happens is a result of everything that comes before it and at the time of you believing you make a choice, that choice is merely the sum of what happened up to that point.
At the time you are making a "choice" you will never pick the less beneficial alternative. You may in hintersight understand your choice to be less beneficial but that doesn't change that you really only had one choice (the one that at the time seemed most beneficial). You make that choice based on many factors, most noteably the sum of your experience up to that point as well as your bodys state which is also the sum of what you did up to that point.
This isn't fatalistic. In fact, this realization helps you to forsee or at least prepare for the future. this idea might actually be beneficial for the rest of your life. Because if you think this makes sense, you may see that accumulating more experience might make you make more beneficial choices in the future. Also, it might encourage you to find reasons for what just happened by looking at the past and make you even more prepared to forsee the future.
But remember that you reach this conclusion because you were inspired by what you were just told. Thus yet again your appearent "change of action" is simply because of this event, which in turn is the sum of everything that happened up to this point.
And if you reach the conclusion like darkling proposed; "it justify being a dick because it was pre-ordained to happen" also that was the only possible conclusion you could draw from what happened prior to this point. Either conclusion reveals something about your past and the kind of person you are.
There is a psychological term called the FAE, the Fundamental Attribution Error. The FAE lead a person to judge a situation only by the easy accessible current information, rather than looking for background information. The idea that people make "choices" in which all "choices" are equally valid to them, is a thought-stopping cliché.
Is Joe nothing more than an alcoholic? If we look at Joe right now, he might be drunken beyond belief. If we only draw our conclusions from that information, we might reach the conclusion that he is in fact, nothing more than an alcoholic. If we instead look at the following three questions;
1. Consensus; What would I be in his shoes?
2. Consistency; Given the situation, would everyone be drunk?
3. Distinctiveness; Is it usually the case that Joe is drunk?
These questions help us to reveal the reasons why Joe made the appearent "choice" he did. The information that when summed up made Joe do what he did.
Understanding the reasons behind an appearent "choice" equips us to nudge future "choices", because we understand that the "choice" is merely the sum of what we do prior to the choice. However, just stopping at the idea "it was a choice" will make us judge Joe for the current situation, without making much improvement for the future "choices" he makes.
The belief in "choice" is the belief that there's no cause. Yet it is self evident that we ourselves always act for a reason.
