For most religious people, this sentence would be blasphemous. God is something ‘external’ to pray to for health, wealth, and forgiveness.
Those same people often like the idea that God is within, that God is Love, or that there is nothing but God. If there is nothing but God, how can He be external?
God wants you to know your self as Him, to know that you are infinite & eternal, created ‘in his image’, unaffected by events and circumstances, all-loving and all-encompassing. Only then can you truly know Peace.
As long as you believe God is somewhere ‘outside’, you will be suffering and full of fear. Once you know yourself as God, the One Being out of which everything is made, you can only laugh at the tiny mad idea of being separate.
All forms are expressions of God, including your mind/body. But you remain infinite, eternal, unbound and unaffected by appearances. All things are made of God. All things are made of You.
I am God is the most devotional statement one can make.