A.T. Robertson Commentary 1 John 3:11

"For this is the message which ye heard from the beginning, that we should love one another:" — 1 John 3:11 (ASV)

Message (αγγελια). In N.T. only here and 1:5, but επαγγελια (promise) fifty-one times.

From the beginning (απ' αρχης). See 1:1 for this phrase and 2:7 for the idea. They had the message of love for the brotherhood from the beginning of the gospel and it goes back to the time of Cain and Abel (verse 12).

That we should love one another (ινα αγαπωμεν αλληλους). Sub-final clause (content of the αγγελια) with ινα and present active subjunctive. John repeats the message of 2:7f.