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]])
"Lead you astray" here is a metaphor, as if one were led off the right path to follow. AT: "do not let anyone fool you" or "do not let anyone deceive you" (See: [[rc://en/ta/man/translate/figs-metaphor]])
This refers to the very earliest time of creation before humans first sinned. AT: "since the earliest time of creation" (See: [[rc://en/ta/man/translate/figs-metonymy]])