I think you’re right when you come to the conclusion that life would be meaningless if we could not escape our preordained destiny. Why would a “higher entity” bother if outcome was known?
You also asked, “Are our lives ruled by our own free will or do we all come with our own destinies? Or is it both?”
What if it is neither? What if free will is an illusion and determinism (causality) only makes sense from the perspective of past events but not future events simply because they haven’t happen yet?
What if there is something else entirely that determines why we behave the way we do? Perhaps there is a second replicator that has co-evolved with us and is so integrated with our minds we don’t see them for what they are – parasites. And what if these parasites do what all parasites do, use their hosts to replicate as much as possible at the expense of the host? Could we ever come to know them for what they really are when people think of them as their most treasured possessions – their beliefs?
I wrote a short post that tries to answer the questions “Are we in control” and “Do we have free will” from this perspective. You can find it here if you’re interested: https://steemit.com/philosophy/@rethinkingbelief/are-we-in-control
Thanks for your post.
Oh yes, our belief system has a huge role to play in determining the choices that we make. Even then the choices are ours to make and hence the free will.