The next phrase talks of the Father bringing everything together under Christ as head of everything in the heavens and everything on earth. This shows the power of God. For him to bring everything together under one person means that the Father will have everything submit to Jesus. Paul also talks of Gods power when he says that God guides all things as he decides by his own will.

The Father is Almighty because he is Creator. The Father is Almighty because he can guide things to fulfill what he has willed. All these he does for the specific purpose of praising his glory. If God can guide all things to fulfill what he has willed, this also means that God is in control.