John 17:23
I in them and you in me, that they may become completely one, so that the world may know that you sent me and have loved them even as you have loved me — The recursive indwelling (I in them, you in me) expresses the mystical union central to Johannine soteriology: believers participate in the divine life through the Son. The world's knowledge of Christ's mission depends on witnessing this internal unity and God's love manifested toward disciples with the same intensity reserved for the Son. This represents the apotheosis of mission theology: love becomes testimony.