Atos 19

Atos 19:5

Of the existence of the Holy Spirit … we are taught in many passages of Scripture. For instance, David says in the fiftieth psalm, "And take not your Holy Spirit from me," and in Daniel it is said, "The Holy Spirit, who is in you." But in the New Testament we have proofs in abundance, as when the Holy Spirit is related to have descended upon Christ, and when the Lord breathed on his apostles after the resurrection and said, "Receive the Holy Spirit," and the angel said to Mary, "The Holy Spirit shall come upon you," and Paul teaches us that "no one can say that Jesus is the Lord except in the Holy Spirit," and in the Acts of the Apostles "through the laying on of the apostles' hands the Holy Spirit was given" in baptism. From all of which we learn that the person of the Holy Spirit is of so great authority and dignity that saving baptism is not complete except when performed with the authority of the whole most excellent Trinity, that is, by naming the Father, Son and Holy Spirit. — ON FIRST PRINCIPLES 1.3.2