1 Love is a sweet word, but sweeter the deed. To be always speaking of it, is not in our power: for we have many things to do, and various businesses draw us different ways, so that our tongue has not leisure to be always speaking of love: as indeed our tongue could have nothing better to do. But though we may not always be speaking of it, we may always keep it. Just as it is with the Alleluia which we sing at this present time, are we always doing this? Not one hour, I do not say for the whole space of it, do we sing Alleluia, but barely during a few moments of one hour, and then give ourselves to something else.
Now Alleluia, as you already know, means, Praise ye the Lord. He that praises God with his tongue, cannot be always doing this: he that by his life and conduct praises God, can be doing it always. Works of mercy, affections of charity, sanctity of piety, incorruptness of chastity, modesty of sobriety, these things are always to be practiced: whether we are in public, or at home; whether before men, or in our chamber; whether speaking, or holding our peace; whether occupied upon something, or free from occupation: these are always to be kept, because all these virtues which I have named are within.
But who is sufficient to name them all? There is as it were the army of an emperor seated within in your mind. For as an emperor by his army does what he will, so the Lord Jesus Christ, once beginning to dwell in our inner man, (i.e. in the mind through faith), uses these virtues as His ministers. And by these virtues which cannot be seen with eyes, and yet when they are named are praised— and they would not be praised except they were loved, not loved except they were seen; and if not loved except seen, they are seen with another eye, that is, with the inward beholding of the heart— by these invisible virtues, the members are visibly put in motion: the feet to walk, but whither?
Whither they are moved by the good will which as a soldier serves the good emperor: the hands to work; but what? That which is bidden by charity which is inspired within by the Holy Ghost. The members then are seen when they are put in motion; He that orders them within is not seen: and who He is that orders them within is known almost alone to Him that orders, and to him who within is ordered.
Source: Homilies on the First Epistle of John (New Advent)