And we are in Him that is true, even in His Son Jesus Christ. This is the true God, and eternal life (I John 5:20).
That the Apostle John is applying the title, the true God, to the Lord Jesus Christ is reinforced when we study the teaching about eternal life in this small epistle. At the beginning, John wrote that eternal Life, which was with the Father, and was manifested unto us (I John 1:2). Eternal life is personified as a Person, Jesus Christ. He was with the Father and was manifested to His disciples on this earth.
Again, in I John 5:11,12, we see that the apostle links eternal life with the Second Person of the Trinity. And this is the record, that God hath given to us eternal life, and this life is in His Son. He that hath the Son hath life; and he that hath not the Son of God hath not life. Life is not an entity that exists apart from the Lord Jesus. When someone asks, How is life treating you? it is appropriate to answer in terms of Jesus, Life Himself (cf. John 14:6). He is treating me with great kindness, is one fitting response.
Of course, the text for the day also links eternal life with Jesus, but note that the phrase, the true God, is sandwiched between his Son Jesus Christ and eternal life. If Jesus is the subject before and after, then the phrase, the true God, applies to Him as well. It is not saying that the Lord Jesus Christ is a god (diminutive sense), but that He is the true God (emphatic sense).
Modern-day cultists set themselves up as experts, pretending to know more about Jesus than the apostles who walked with Him, but John wrote about being in Him that is true (first part of todays text). The important lesson for us is to connect personally with this true God, Jesus Christto be in Him. Jesus is not a distant, dead memory, but the One who enlivens even deluded errorists. We enter into communion with Him by faith. PGH