Over here, Frater R.O. argues that everything happens for a reason.
Over here, Jason Miller says that's poppycock, and not everything happens for a reason.
I was just thinking about this myself (Thanks again, Abrimelin Synchonicity!), and so thought I'd add my thoughts.
They're both right.
Ok, I'm a non-dualist, so it's perfectly rational in my view for both perspectives to be correct.
It may be that everything happens for a reason, in the sense that event D is the result of events A, B, and C. I'm alive today because when I took the kayak out in the lake when I was 5, when I couldn't swim, and didn't understand how paddles worked, A) I didn't panic, and B) someone came by and rescued me. I was in danger because I took the kayak out in the lake, couldn't swim, and didn't understand how paddles worked. So, both things happened for a reason, and those reasons are easily explained. That's simple cause and effect.
Now, does this mean I have some great destiny? Nah. Well maybe.
While I like Frater R.O.'s big harmonious machine vision, one of the wonderful things about machines is that if one part doesn't work correctly you can replace it with another one.
Let's say the Harmony model is correct, and the universe runs like a big orchestra. When you need a violin to play in a certain section, you don't need a specific player. You simply need the notes. Certain players will work better than others, will bring a certain flair or mastery to the piece, but as long as the right notes are played, the harmony is maintained.
In a similar way, if there's a grand plan/vision/type thing for the universe, certain things will have to be done in a certain order, a certain way. Who does them is immaterial.
So, the celestial and infernal beings try to influence us to play our parts. Mankind is recalcitrant, has eaten from the tree of knowledge, and if the Bible shows us anything, does not know it's place in the scheme of things. We insist we are gods, we are worms, we are destined, we are adrift. We are human. We err. (Often, according to Yahweh). To base your machine on things that err without having a contingency plan is not a course of action one attributes to the Great Architect.
IMHO, The Harmonious machine is not some fixed, perfect thing, either. It evolves as things work and things don't. This, of course, speaks directly to me as a Gnostic and a software professional. The Demi-Urge has this huge vision and plan, which is WAY beyond his ability to realize. So he builds the imperfect thing that does most of what he wants, and releases updates and improves the machine as he goes along, finding flaws, correcting them, removing parts, installing new programs that may cause problems. One can see this in the ongoing pattern of revelation (Old Testament, New Testament, Gnostic controversies, Medieval Scholasticism, Reformation, Enlightenment, etc.)
So, there are parts that are predestined. The material part sure is: We're born, and everything beyond that follows a certain course most of the time (Growth, peak, decay, death). The spiritual and part of us deemed "The Will" is much less determined. For every one of us who takes part in the great, harmonious machine, how many parts are discarded as unworthy, as not fitting the pattern, as simply off the track? The Divine Judge separates the Wheat from the Chaff.
None of this, to me, speaks to the Gnostics True God, the Unapproachable Divine. Everything is contained within that, and there is no duality there, so harmony or lack thereof is not an issue.
To sum up: There is a destiny. There is a place for us in the celestial hierarchy. Whether that place is crucial to the harmonious machine or not is determined by our free will. There are crucial places, and people step up to them, much like a soloist. There is also the choir, and the audience. Free will determines your personal position, predestination determines that there are certain positions that must be filled. It's a matter of perspective, like most things.