Premanand Maharaj Ji
Why did God create the world if He was going to destroy it?
Creation is God's play
God creates, sustains and destroys as Brahma, Vishnu and Shiva, and it is His play. The question "why did He do this?" arises because we speak from the body feeling.
In the whole creation God performed three leelas: creating as Brahma, sustaining as Vishnu, and destroying as Shiva.