"And Jesus advanced in wisdom and age and grace with God and men." (St Luke ii, 42)
This morning — which in the Ordinary Form of the Mass is the feast of the Holy Family (in the Breviary, it is the Sunday in the Octave of Christmas), and which had the Gospel of the Finding of Our Lord in the Temple — Fr Peter, our Dominican visiting priest at Carmel, preached on the necessity of family to Christ, that in His humanity He grow up and develop: for as all men, the Son of Man could not grow up isolated and alone, but was formed as to His human nature as a member of society, needing parents, relations, friends and acquaintances; for "no man is an island" - man is a social animal.
Our Lady was not merely Mother of Christ, but a Mother to Christ; and it was needful for St Joseph to be a true foster-father to Our Lord, not merely a breadwinner for the Holy Family, but a true father figure, teaching his putative Son how to live as a man by his example. This is because Christ was true Man as well as true God, and therefore according to His human nature truly and not in similitude learned and grew up through experiential knowledge, as all men do. Hence "He was subject to them" (St Luke ii, 51).
The Holy Family had gone up to Jerusalem for the feast, as usual — just as we go to Sunday Mass as usual. But then, consternation! They looked for Him "everywhere": note the poignant choice of word. Yet they found Him about His Father's affairs, in His Father's house, and were not able then to quite grasp the situation (St Luke ii, 49-50). Our Lord's answers more than satisfied the doctors of the Law as He sat with them the Temple; but His answer did not at once explain matters, not to Our Lady, not till she took it to her heart (St Luke ii, 51), turning it over and pondering on it.
Faith is like this — it is not an entire explanation to us, not this side of the Beatific Vision; it is what we lay hold of, "the assurance of things hoped for, the proof of things not seen" (Heb. xi, 1), but what we struggle to understand; difficulties, "doubts" in the improper sense, are a part of our life of faith, in the darkness of our earthbound understanding of matters above: the lack of clarity is because the light is in a sense too strong, rather than not strong enough. But we must not be discouraged, and rather hold on to our faith. "It is as a lamp shining in a dark place..." (cf. St James i, 19 - writing of the Scriptures).
(This seems to me somewhat of the gist of the homily.)