An Arab Poet, Elya Abu Madhi (a born-Christian), not long ago expressed his uncertainty about the purpose of life in his Arabic poem Al-Talasim, He says in his poem:

I came not knowing from where, but I came.
And I saw a pathway in front of me, so I walked.
And I will remain walking, whether I want this or not.
How did I come? How did I see my pathway?
I do not know!
Am I new or am I old in this existence?
Am I free and unrestrained, or do I walk in chains?
Do I lead myself in my life, or am I being led?
I wish I know, but…
I do not know!
And my path, oh what is my path? Is it long or is it short?
Am I ascending in it, or am I going down and sinking?
Am I the one who is walking on the road,
or is it the road that is moving?
Or are we both standing, but it is the time that is running?
I do not know!
Before I became a full human, do you see
if I were nothing, impossible? Or do you see that I was something?
Is there an answer to this puzzle, or will it remain eternal?
I do not know ... and why do I not know??
I do not know!