Commentaries:
John appeals to the brethren to hold fast to the truth that they had been taught since their calling. To "abide" in the Son and the Father means to remain faithful to God's way of life, grow spiritually, and become more and more like God (John 15:4-6).The only way we can do this is by remaining faithful to the truth of God that the apostles taught from the church's founding. To those who remain faithful to His way, God has promised eternal life (I John 2:25).
Earl L. Henn
For the Perfecting of the Saints