And hereby we do know that we know him, if we keep his commandments.
We know that we have come to know him if we keep his commands.
Καὶ ἐν τούτῳ γινώσκομεν ὅτι ἐγνώκαμεν αὐτόν, ἐὰν τὰς ἐντολὰς αὐτοῦ τηρῶμεν.
Kai en toytō ginōskomen oti egnōkamen ayton, ean tas entolas aytoy tērōmen.