The third book continues the same argument, showing that the mission of prophets and apostles, and even of the Son Himself, is to be referred to the Spirit, yet without any subjection on the part of the Son, seeing that the Spirit also receives His mission from the Father and the Son. The Godhead of the Holy Spirit is next taken up and proved, when occasion is taken also to show that there are not three Gods or three Lords, for the Three Divine Persons are one in holiness and nature; and the work is concluded with a summary of some of the principal arguments.