IS GOD REALLY ALMIGHTY? IF SO, WHY DOES EVIL EXIST ON EARTH?
First we should know why we address God Almighty as "God Almighty". It is not only to denote that He is the mightiest spirit of the good Spirit World but also because there is no other power above Him. No other angel or archangel has any power that is above God Almighty's. If God Almighty says 'yes' or 'no' to anything then there is no further appeal.
To understand why evil exists against the desires of God Almighty we need to go back in time. At first, God created Earth for mankind to live very happily and to progress it. God wanted that souls of the heavens visit Earth as humans, and be in charge of Earth and progress it. Mankind did so, and Earth became a very good place to be. This attracted evil and evil also desired a place on Earth. So evil then influenced man to create some creatures which conflicted with God's plan for Earth. So God sent His angels to destroy these creations that mankind had made. To this, mankind protested. If humans were to be in charge of Earth and progress it in their own way, then the interference of the angels was conflicting with their purpose on Earth. God agreed to this, and then an agreement was made between God and mankind. The agreement was that souls of heavens should not have a command over mankind, and that they should only come to Earth by birth or with the permission of man and God, or come when mankind needs the heaven's help and only when they ask for it. With this agreement, mankind started living a relaxed life, spending less time to progress and more time doing nothing. This was the easiest way for evil to influence and convince mankind to share Earth with them. To this, mankind at first said 'No'. But evil was persistent, and since no agreement existed between evil and mankind, evil was able to offer comforts for mankind to make life easier for them. In this way, evil was slowly able to creep into human bodies. So when evil attracted mankind by the earthly comforts that they could offer, mankind invited them to stay on Earth.
Now only if and when mankind itself wants to be free of evil and only at a stage when mankind itself will not be strong enough to get rid of evil and only if mankind will ask for heaven's help, will God then come to the rescue. Therefore, evil is here to stay until all good people have had enough of the evil and then cry for God's help. Only then will God show His might and we will witness it when the time is right. Again, God has concerns about the happenings in His domain only. God is not all out to destroy all evil but He is all out to remove all evil from within His domain and as far as Earth is concerned - at the request of mankind.