In John 14:10-11, Jesus makes a staggering statement. The Father dwells in the Son, but also, at one and the same time, the Son dwells in the Father. More than this, the Spirit too is in both the Father and the Son as they are within him.
This is not merely an overlap, a Venn diagram of overlapping circles, which would suggest a kind of tritheism with each only partly divine. No, it is complete and total immersion as it were, a total union, because the Father and the Son and the Holy Spirit each fill the whole divine space, as it were, and so completely fill one another.
Nor is it like gases or fluids which can completely intermingle with each other; then each would lose his identity. The Father would no longer be distinct as Father, the Son as Son, and the Spirit as Spirit. Yet each retains eternally his own identity, distinct from the others.
Garry Williams quotes Hilary of Poitiers on this: 'It seems impossible that one object should be both within and without another, or that (since it is laid down that the Beings of whom we are treating, though They do not dwell apart, retain their separate existence and condition) these Beings can reciprocally contain One Another, so that One should permanently envelope, and also be permanently enveloped by, the Other, whom yet he envelopes.'
This speaks of a personal closeness beyond our understanding.
