1 John 5:2

Ἐν τούτῳ γινώσκομεν ὅτι ἀγαπῶμεν τὰ τέκνα τοῦ Θεοῦ, ὅταν τὸν Θεὸν ἀγαπῶμεν, καὶ τὰς ἐντολὰς αὐτοῦ τηρῶμεν.

En toytō ginōskomen oti agapōmen ta tekna toy Theoy, otan ton Theon agapōmen, kai tas entolas aytoy tērōmen.

King James Version (KJV)

By this we know that we love the children of God, when we love God, and keep his commandments.

Modern English

This is how we know that we love the children of God: by loving God and carrying out his commands.