"The end is first in the order of intention": humans act on a means-to-ends basis,
Not when it comes to life. Nobody is born looking forward to the day they die, we look foreword to each stage in life.
The more exalted the end, the more meaningful and fulfilling the means. If someone's ultimate end is pleasure they will inevitably lead a relatively shallow and unfulfilled life.
You make the common mistake of assuming nobody finds pleasure in things that are constructive like helping others, or improving lives. Don’t assume pleasure equals selfishness, even if your religion teaches you to think that way.
Indeed, any finite end found in our fallen state--things that are good in themselves--are not ultimately fulfilling.
That might be the case for you, but you aren’t qualified to speak for everybody else. What is ultimately fulfilling is subjective; meaning it varies from person to person. So you aren’t qualified to tell me (or anybody else) what I find ultimately fulfilling.
This is why people search for God or transcendent realities, because they have desires that surpass the possibilities of what can be accomplished on their own.
Here I agree. There are many people who are unable to find worth, fulfillment, purpose, or meaning on their own and feel a need to look outside of themselves for these things. Not everybody is this way (myself included) but many people are.
Of course one can squelch that desire for God and unconditioned happiness, but to squelch such a fundamental and high principle will have a domino effect on every means-based action in life.
Not everybody who finds their concept of God, has an improved life as a result. History is full of examples of people whose lives have turned for the worse after believing they've found God.
The journey makes no sense apart from the destination,
That’s only for you, probably because you’ve invested your life in the destination. For me, my life is invested in the journey; the destination has no value for me.
and it is precisely the glimpses and foretastes of the destination that make the journey bearable and even at times enjoyable.
If your journey through life is that miserable because of your religion, it sounds like you might be better off with without it. Speaking for myself, when I was finally able to free myself from theistic chains, and enjoy life for what it is, though it was the most difficult thing I've ever done, it was definitely the best thing I could have ever done; my life is better because of it.
