He is called "eternal life" becasue he gives us eternal life. AT: "and the one who gives eternal life" (See: [[rc://en/ta/man/translate/figs-metonymy]])
John was an elderly man and their leader. He used this expression to show his love for them. See how you translated this in [1 John 2:1](../02/01.md). AT: "My dear children in Christ" or "You who are as dear to me as my own children" (See: [[rc://en/ta/man/translate/figs-metaphor]])