If God is willing to destroy evil but not able to, then he is not all powerful.
If God can destroy evil but chooses not to, then he is responsible for all evil.
If God can destroy evil and chooses to, then evil cannot exist.
If God is not able to and is not willing to destroy evil, then he is not God.
Is God willing to prevent evil, but not able? Then He is not omnipotent.
Is He able, but not willing? Then He is malevolent.
Is He both able and willing? Then whence cometh evil?
Is He neither able nor willing? Then why call Him God?
-Epicurus
God created the beings who choose to do evil -because choice was required due to the desired end result of making gods -so eradication of evil requires that those beings no longer do evil -or that those beings no longer exist.
God is able to destroy both body and spirit in Gehenna -but it is his will that we turn from evil instead. God could conceivably destroy evil today -by destroying all who have the ability to choose it.
As he declared the end from the beginning, evil wIll certainly eventually be eradicated -but he bears with it for a time so that we have the time to overcome it.
Is it more loving to destroy us all now -or to see us through this time and make us gods?
Evil is essentially disorder. Good is a perfect system, and evil that which brings it into disorder and imperfection. It takes time for new beings to learn order -learn their place in the order of things -to become ever greater in an orderly fashion -and learn to maintain order in themselves and their environment.
As for God doing evil through natural disasters, etc.......
The tree of life included an ordered and maintained environment -and the creation was given over to disorder when the tree of life was rejected.
God also uses adversity to accomplish his purpose.
God is quoted as saying that he "purpose"s evil -and he does purposefully do things which can be broadly seen to be evil in a sense -but which work good overall -and is not literally evil.
Everything he does will accomplish good -even for those on the receiving end of the more extreme things.
Plagues, curses, storms, animals, insects -directing human armies against other humans -even allowing demons to enact their will -all have been employed by God -yet he remains blameless.
How? God is the one who can raise every last one of the dead, and repair any thing which has been destroyed. That which he does and allows is always necessary for our eventual good.
That cannot be said of others.
All who have been on the receiving end of the evil God has "purposed" will reap the benefits of the overall results.
Many lost their lives by the death penalty under the Old Testament judgments -but that prepared the way for the new covenant -which will result in men being made immortal and ruling Earth under Christ. The earth will become a paradise. After a thousand years, all who have ever lived will be resurrected to that situation and judged according to their works.
They will then be taught to do well in that environment and also have the opportunity to live forever and create throughout the universe.
Yes -God killed them -but did so to make the future possible. Then he un-kills them -wipes away every tear -and the former things will not be brought into remembrance.
Our environment is that by which our minds are manufactured.
The adversity we live through has a psychological effect -and more positively so if we choose to overcome that adversity.
God said he would try us and refine us as gold and silver.
Then... When our minds have been perfected, we can be given a perfect body, and the environment can be repaired. In fact, the bible specifies that the bodies we may be given will have power similar to that which allows God and Christ to subdue all things unto themselves.