1 John 4:6

We are of God: he that knoweth God heareth us, &c. Even as Christ saith, "He that heareth you, heareth Me: he that despiseth you, despiseth Me," We, i.e., all the faithful, who have been born again in baptism, and are endued with charity. We, viz. the predestinated. 3d. And last: We, i.e., the Apostles. For, as Œcumenius says to heresiarchs, who, he said, spoke of the world, and from the world i.e., who teach worldly and carnal cupidity to them he opposes the Apostles, who being born of God, and imbued with heavenly doctrine, and being sent by God, teach men to covet things spiritual, divine, and heavenly. Wherefore he who practically knows God, i.e., he who loves Him, heareth us, i.e., me John, and the rest of the Apostles, and Apostolic men. But he who does not love God, and therefore is not of God, but of the world, this man heareth not us. Wherefore he adds, By this we know the spirit of truth, and the spirit of error; by this, namely, "because he that heareth us hath the spirit of truth, he that heareth not us hath the spirit of error," as S. Augustine saith. For heretics, who are led by the spirit of error, teach the things of the world: but the Apostles and Apostolic Doctors, who are born of God, teach things Divine.