Let us continue to “consider Jesus.” (Heb. 3:1)
1 Jn. 5:19,20 “We know that we are from God, and the whole world lies in the power of the evil one.” 20 “And we know that the Son of God has come and has given us understanding, so that we may know shim who is true; and we are in him who is true, in his Son Jesus Christ. He is the true God and eternal life.” ESV
The last statement of 1 Jn. 5 :20 is a summary and restatement of the truth John had explained at longer length above. Some translations give the restatement as “He is the true God…” and others, “This is the true God…” Some think summary states that the God with us the true one and Jesus His son is the way of eternal life. This is true. Others think this summary states that Jesus Himself is the true God and is the way of eternal life. This is true as well. Which of these senses John means here, you may decide for yourself.
When John uses the phrase, “The true God” it is to tie belief in Jesus with Jehovah, the living God of in the Old Testament (Ref. 2 Chron. 15:3; Jer. 10:10) as is also done by Jesus Himself and Paul. (Jn. 17:3; 1 Thess. 1:9)
This great continuity of truth embodied in Jesus is the source of our salvation. He is the true God.