1 In the preceding lesson of the holy Gospel, which is followed by the one that has just been read, the Lord Jesus had said that He and the Father would come to those who loved Them, and make Their abode with them. But He had also already said above of the Holy Spirit, “But you shall know Him; for He shall dwell with you, and shall be in you”: by which we understood that the divine Trinity dwells together in the saints as in His own temple. But now He says, “These things have I spoken unto you while [still] dwelling with you.”
That dwelling, therefore, which He promised in the future, is of one kind; and this, which He declares to be present, is of another. The one is spiritual, and is realized inwardly by the mind; the other is corporal, and is exhibited outwardly to the eye and the ear. The one brings eternal blessedness to those who have been delivered, the other pays its visits in time to those who await deliverance. As regards the one, the Lord never withdraws from those who love Him; as regards the other, He comes and goes. These things, He says, “have I spoken unto you, while [still] dwelling with you;” that is, in His bodily presence, wherein He was visibly conversing with them.
Source: Tractates on the Gospel of John (New Advent)