What is the mystery in this? Every intelligent child is supposed to understand this simple fact. There is only One Creator, Allah Ta’ala. There are not more than one Creator. Your question should not be difficult to fathom. Who created Shaitaan? Is the Shaitaan not the embodiment of evil? Who created the nafs which is the epitome of evil? Allah Ta’ala has created both good and evil. He gave us Aql (intelligence), willpower and the teachings of the Ambiya to aid and guide us through this worldly life strewn with the thorns of evil which Allah Ta’ala has created to try and test us.