Not necessarily. I think that we can imagine our lives having individual purposes without necessarily implying the existence of any single cosmic purpose.
Would you also say that an individual person can have a purposeful life in a purposeless universe?
If a person is a part of the universe and functions by the same principles as the universe, how would it be possible for the person to have a purposeful life in a purposeless universe?
After all, even if God (or the universe) does have a purpose, some transcendental teleological goal that everything is moving towards, that purpose will still be God's and not ours.
But if in that scheme of things, we belong to God, then there's no problem with that purpose being God's and not specifically of our invention.
We might still say -- "Yeah, it's great that God has a purpose in creating all this, but what about ME? What about my life??"
This is an issue that would arise if whom we presume to be God, would actually be merely a demigod.
Whatever grand cosmic purpose that might exist still won't be of any use to individual human beings until we can bring it down to our own scale and internalize it somehow in our lives, until we identify with it and make it our own.
Sure.
That's the thing... I don't really see a whole lot of distinction between 'God' on one hand, and 'ultimate meaning in the cosmos' on the other. They both seem to me to refer to pretty much the same idea, except that the former is sometimes imagined in a more personal way. In both cases, the seeker is looking for some giant cosmic scale... something... that gives direction to their life and ensures that everything's going to be worthwhile.
It follows that if one is part of the universe, then one functions by the same principles as the universe. What precisely those principles are is open to inquiry, although some people have concluded on one extreme or the other (usually with materialistic impersonalist reductionsm on the one hand, and anthropomorphic idealism on the other hand).
Be that as it may, the idea that one's own purpose and the cosmic purpose are intimately related is based on the idea that one, ie., a human, is part of the universe. This is hardly a controversial idea.
Even if the universe is headed towards some grand teleological end, I'd still have to learn about it, embrace it somehow, and then incorporate the cosmic motion towards that destination into how I conceive of my own life.
Arguably, if such a teleological end exists, and you are part of the universe, then you are already working toward that end, inevitably, and don't really have to do anything in particular about it. Ie. simply in "minding your own business", you are working toward that end, there being no need to learn about it or embrace it etc.
IOW, it seems that the problem may be somewhere else, and that the question may have to be put differently.
Which leaves the unrequited desire hanging. Maybe that's one of the things that's attracted me towards Buddhism.
Desires arise and pass away.
I'm just not convinced that the cosmos as a whole is striving towards the same sort of ends that I find myself seeking in my own life.
As with many true nature arguments, one usually shoots oneself in the foot with them.
That is, to give some examples, if we posit that man's true nature is good, we end up with one set of problems (such as why do bad things happen to us, if we're innately good); if we posit that man's true nature is bad, we end up with another set of problems (why bother with anything?); if we posit that the purpose of life is to procreate, then what about those people who don't procreate, are they doomed to live a meaningless life; if we posit that the purpose of life is to learn and understand, then how do we explain the life of those who die as infants, or who never seem to learn and understand ... etc. etc.
IOW, it tends to happen that the moment we posit that the true nature of something, or that the true purpose of something is such and such, we either posit it as something so vague that it is useless, or limit it in such a way that we end up unhappy with our proposition or its applications and implications.
Which is why it is pragmatic to put true nature/true purpose arguments aside for the time being. Not because such a true purpose or true nature wouldn't exist, but because we simply don't know them and can only speculate about them. And there are some things which, if we speculate about, are
bound to make us go mad, so it's best not to speculate about them.
Warmly recommend:
Freedom From Buddha Nature
What is Wrong with Buddha Nature