Why does God not destroy evil if He is omnipotent?

If God destroyed evil, your evolution on earth would stop dead. 

There would be no need to struggle with nothing to struggle against. 

Automatic goodness would be the result, which is not what the Almighty God intends. 

His plan is that through endless trials and many failures you at last obtain your final victory and stand before Him in all the cleanness, beauty and strength of the Master Christ himself. 

It is because the great God has chosen to withhold His omnipotence in that direction that you can reflect the greater glory―

Not an automaton, but a free agent with the seeds of immortality and divinity contained in your ego from the very beginning.