And he in him (kai auto en autwi). That is "God abides in him" as in John 4:15 . We abide in God and God abides in us through the Holy Spirit ( John 14:10John 14:17John 14:23 ; John 17:21 ). "Therefore let God be a home to thee, and be thou the home of God: abide in God, and let God abide in thee" (Bede). By the Spirit (ek tou pneumato). It is thus (by the Holy Spirit, first mention in this Epistle and "Holy" not used with "Spirit" in this Epistle or the Apocalypse) that we know that God abides in us. Which (ou). Ablative case by attraction from accusative o (object of edwken) to agree with pneumato as often, though not always. It is a pity that the grammatical gender (which) is retained here in the English instead of "whom," as it should be.