I wrote the following in response to a friend who was saying there was no obvious purpose, and quoting Kierkegaard on how we create our own purpose until we realize it is absurd:
I believe there is a purpose, and our purpose is "joy," and suggest that we are at the very initial phase in achieving that purpose. We are learning the extent of what is Not Joyful, so that as we one day arrive at the final phase -- where all is Joy -- we have no doubt whatsoever that we have exhausted all possible alternatives wherein joy is less. To have no doubt is to be absolutely certain.
Having certainty that our joy is not lacking makes for a "fullness of joy," since due to our certainty we seek not to revisit this present miserable stage where joy is so meager. (Otherwise we might arrive at the pinnacle of joy and want "more," which would then not be a full joy. We must exhaust imperfection before we arrive at joy, not after.)
What do I mean by joy? Given that our greatest joys seem to come by unification between souls, perfected joy is something like this: for each individual will to be intimately aware of every experience that every other creation is experiencing -- all simultaneously. I believe this is what our Creator experiences continually. It is where we came from, and it is where we are headed. However, to hold this position properly requires maturity (so that we can have that intimate experience of All without interfering with others' free agency). To model this maturity for us, our Creator does not interfere with our free agency... unless we specifically ask. This non-interference in our agency appears to some to be indifference, but in fact it is the backbone of our future joy. How can we be trusted to allow others the full range of experience without interfering, unless that has been forged within us, as we are experiencing now?
Lack of joy is therefore to only be able to experience your own lonely part of the whole, to doubt the meaning or purpose of the whole, to get bored with the whole, or even to get stuck attempting to subtract oneself from the whole... and that is what we learn about here in mortality if we are paying attention.
I agree with Kierkegaard that we create our own purpose, but believe we can achieve the essential proof-of-absurdity-of-our-purpose here in this lifetime. Once that happens, we can sit and spin for as long as we want (depressed) or we can relinquish the "ashes" of our own self-made purpose in exchange for the "beauty" delivered by the Holy Spirit (delivered continually to everyone always, but not always received by those who are busily proving their own absurdity), which transforms our desires from individual joy to universal joy, and draws us back, like a phoenix rising from our own ashes, to the heaven from which we came (which is within, by the way) in order to learn about boundaries.
*Isaiah 61:2-7 "...to comfort all who mourn, and provide for those who grieve in Zion -- to bestow on them a crown of beauty instead of ashes, the oil of joy instead of mourning, and a garment of praise instead of a spirit of despair. They will be called oaks of righteousness, a planting of the Lord for the display of his splendor. They will rebuild the ancient ruins and restore the places long devastated; they will renew the ruined cities that have been devastated for generations. Strangers will shepherd your flocks; foreigners will work your fields and vineyards. And you will be called priests of the Lord, you will be named ministers of our God. You will feed on the wealth of nations, and in their riches you will boast. Instead of your shame you will receive a double portion, and instead of disgrace you will rejoice in your inheritance. And so you will inherit a double portion in your land, and everlasting joy will be yours."