We write these things so that our joy may be complete.
Observe here, The great end for which the apostles penned and wrote the doctrine of the gospel, namely, that their joy may be full who do believe it and obey it. The joy which good men experience in the word of God, is a solid joy, a substantial joy, a full joy, a lasting joy.
these things--and none other, namely, this whole Epistle. write we unto you--Some oldest manuscripts omit "unto you," and emphasize "we." Thus the antithesis is between "we" (apostles and eye-witnesses) and "your." We write thus that your joy may be full. Other oldest manuscripts and versions read "OUR joy," namely, that our joy may be filled full by bringing you also into fellowship with the Father and Son.
Verse 4. And these things write we unto you. These things respecting him who was manifested in the flesh, and respecting the results which' flow from that. That your joy may be full. This is almost the same language which the Saviour used when addressing his disciples as he was about to leave them, (;) and there can be little doubt that John had that...