Many people naturally wonder where God came from. Who, or what, made God?
That is a question Christianity does not address. Christianity simply says God has always been.
The same is true for the entire spiritual realm. Christianity says God created the physical realm—the universe, the world, and life on earth. But Christianity does not say God created the spiritual realm. Christianity says God created some spiritual beings, “His” angels, as the Bible puts it. But Christianity does not say God created the entire spiritual realm. Christianity does not say God created all beings in the spiritual realm.
Just like the origin of God, Christianity does not address the origin of the spiritual realm.
Remember, Christianity does not attempt to answer all questions. Some things are simply beyond human understanding.