The only thing God can't do is to do anything wrong or evil. God is absolutely pure and holy, and He cannot do anything that would violate His character or contradict His Word. He cannot lie, nor can He ever approve of anything evil. The Bible says, "The Lord is righteous in all his ways and loving toward all he has made" (Psalm 145:17).
But God isn't only perfect - He is also powerful. If God was powerful enough to create the whole universe, isn't He also powerful enough to overcome every kind of evil - even Satan himself? Of course He is. As the prophet Jeremiah said, "Ah, Sovereign Lord, you have made the heavens and the earth by your great power.... Nothing is too hard for you" (Jeremiah 32:17).
Evil is strong, and we must never underestimate its power. Behind it is the supernatural power of Satan, whose goal is to oppose God in every way possible. But God is stronger than Satan, and some day the final battle will be fought and God will emerge victorious. Some day, the Bible says, all evil will be destroyed and Satan will be bound forever (see Revelation 20:10).
But we don't need to wait until then to know if God is going to win! By His death and resurrection Jesus Christ conquered forever the powers of death and Hell and Satan - and if we know Him, we know our salvation is secure. Put your life into Christ's hands and receive His gift of eternal life today.