But by this one God, Who is good, we must not only understand the Father, but also the Son, who says, “I am the good Shepherd;” [John 10:11] and also the Holy Ghost, because it is said, “The Father which is in heaven will give the good Spirit to them that ask him.” [Luke 11:13] For the One and Undivided Trinity itself, Father, Son, and Holy Ghost, is the Only and One good God. The Lord, therefore, does not deny Himself to be good, but implies that He is God; He does not deny that He is good Master, but He declares that no master is good but God.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).