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

From the beginning (απ' αρχης). See 1. John 1:1 for this phrase and 1. John 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 1. John 3:12).

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 Rev 1. John 2:7.