en_tn/1jn/05/20.md

Son of God

This is an important title for Jesus that describes his relationship to God. (See: rc://en/ta/man/translate/guidelines-sonofgodprinciples)

has given us understanding

"has enabled us to understand the truth"

we are in him who is true

"we are related as closely as possible to the one who is true"

him who is true

"the true one" or "the real God"

This one is the true God

Possible meanings are 1) "This one" refers to Jesus Christ, or 2) "This one" refers to the one true God.

and eternal life

He is called "eternal life" becasue he gives us eternal life. Alternate translation: "and the one who gives eternal life" (See: rc://en/ta/man/translate/figs-metonymy)