Do you not understand that the devil is a human creation and not a reality? God is. God is all that is. God is all goodness and love. THAT is the only power that is. All else is a lack of God-power. “How can this be?” you ask.
What is darkness? Is it a real thing? Does it have power? No. It is merely the lack of light. What is evil? Is it a real power? No. It is merely a lack of Love.
The devil exists only within human consciousness, and only if you allow this false creation into your reality. To the one who truly knows God, the devil is not a power. Evil is a human trait. Rise above your humanness to the conscious vibration of Spirit. There you will find no evil and no devil, for imbued with the consciousness of Light, there can be no darkness.