It was not that the Son of God condemned the assumption of so religious a name; that is, condemned them for professing to be the sons of God, and calling God their Father; but that He blamed the rash presumption of the Jews in claiming God for their Father, when they did not love the Son. For I proceeded forth, and came from God. To proceed forth, is not the same with to come. When our Lord says that those who called God their Father, ought to love Him, because He came forth from God, He means that His being born of God was the reason why He should be loved: the proceeding forth, having reference to His incorporeal birth. Their claim to be the sons of God, was to be made good by their loving Christ, Who was begotten from God. For a true worshipper of God the Father must love the Son, as being from Godf. And he only can love the Father, who believes that the Son is from Him.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: vi. de Trin. c. 30