Verse 6.— We are of God. Here, I think, the writer, by the word "we," means the apostles. They were clothed with miraculous or God-given powers, by which they could demonstrate that their message was from God. Now, a teacher who knows God, will hear us apostles and acknowledge our authority. A teacher that will not hear us as God's messengers is not of God. Hereby know we the spirit of truth. By this mark we can know whether the teachers that come among us are inspired by the spirit of God, or the spirit of the devil.