A.T. Robertson Commentary 1 John 1:4

"and these things we write, that our joy may be made full." — 1 John 1:4 (ASV)

We write (γραφομεν ημεις). Literary plural present active indicative of γραφω, which see in the singular in 2:12-14.

May be fulfilled (η πεπληρωμενη). Periphrastic perfect passive subjunctive of πληροω, stressing the state of completion in the purpose (ινα), remain full, precisely as in Joh 16:24. See aorist subjunctive in Joh 15:11 and perfect indicative in Joh 17:13. The MSS. differ as often between ημων (our) and υμων (your).