Are you asking purely from a Muslim point of view?
Hope not!! Going to give you mine anyway
I'm a Christian, so you know my aganda, and a pretty evangelical one at that, but I don't bite (lol)
I see the reason for my creation to be love. Before the creation of the world, God existed as the Trinity, Father, Son, Spirit, all Loving each other even though there was nothing else to love. Creation occured as the overflowing of that love - God loved so much that He could do nothing else but create out of that love.
The Shorter Catechism (and this is the only bit of it I know!) asks 'what is man's cheif end' which is, of course, what is the purpose of humanity's creation? The answer is 'to love God and enjoy Him forever'
Who am I? I am in Christ, a new creation. THe old has gone, the new has come.
Nice to meet you all!!