Why does God use evil or cause harm to others? Like when the Egyptians were crossing the red sea and the Israelite were after them God told Moses to stretch his stick over the water and it covered the Israelite and they died?
I don’t think there was really anything evil about God telling Moses to let the Red Sea come down on the Egyptians.
1). God, being the author of life, has the authority to do what he wants with that life that he has granted to all living creatures. Think of it like this: you plant a garden. You plant exactly what plants you want to be in this garden and where they are to be. However, some of them stop producing what they should (be it fruits, vegetables, or simply flowers). Since it is your garden, there is nothing evil with pulling those plants up and disposing of them.
2). God was protecting his chosen people Israel. They were otherwise going to be hurt, murdered, and brought back into slavery. If there was a group of men coming after your children with these goals in mind, I don’t think anyone here would disagree with you defending your children.
God is all good. He doesn’t cause evil and he doesn’t actively use evil as a means. God, being all good and all powerful, is able to ALLOW evil to enter our lives only because he is so powerful that he is able to bring forth good from it. According to my understanding (and anyone please correct me if I’m saying things in contradiction to Church teaching), God allows evil and is able to bring good out of it, but he doesn’t directly use evil (for instance, God doesn’t actively cause someone to get murdered to cause something else to happen, but he is ultimately able to bring about some good from this unfortunate and evil scenario.)