Why did it take Allah 6 days to create the universe?
I know that Allah is independent of time, but I have trouble understanding why the creation of the universe took as long as it did. Please help me to clarify that.
Allah created universe in 6 days doesn't mean he could't create it in the trillion'th of a second. It didn't take Allah 6 days(or time periods) but Allah did this intentionally. Allah is "Ala kuli shai'in qadir' - able to do all things.
Now why He chose six days instead of infinite part of a second is His wish. We can think of possible reasons:
Reason 1: Allah doesn't need us we need Him. He doesn't need universe but everything in universe needs him. Since this world was created to test us, so creating it in stages helped human beings to understand it and praise His glory. There is a good proportion in our intelligence and the speed at which things got created in this universe so that we can study them through science. This is just an opinion.