“We however believe that there are three persons, Father, Son, and Holy Spirit, and at the same time we believe nothing to be uncreated but the Father. We therefore as the more pious and the truer course, admit that there are things were made by the Logos, and that the Holy Spirit is the most excellent and the first in order of all that was made by the Father through the Word. (Origin, Commentary on John, Bk. 2, Chap. 10) 

Fr. Robert Barron the Trinity, The Catholicism Series –