6 See, brethren, how many things we pass, in which is not the end. These we use as by the way; we take as it were our refreshment at the halting places on our journey, and pass on. Where then is the end? “Beloved, we are sons of God, and it has not yet appeared what we shall be;” here is this said, in this epistle. As yet then, we are on the way; as yet, wherever we come, we must pass on, until we attain unto some end. We know that when He shall appear, we shall be like Him, for we shall see Him as He is.
That is the end; there perpetual praising, there Alleluia always without fail. This, then is the end he has spoken of in the Psalm: “I have seen the end of all perfection:” and as though it were said to him, What is the end you have seen? “Your commandment, exceeding broad.” This is the end: the breadth of the commandment. The breadth of the commandment is charity, because where charity is, there are no straits. In this breadth, this wide room, was the apostle when he said, “Our mouth is open to you, O you Corinthians, our heart is enlarged: you are not straitened in us.” In this, then, is “Your commandment exceeding broad.”
What is the broad commandment? “A new commandment give I unto you, that you love one another.” Charity, then, is not straitened. Would you not be straitened here on earth? Dwell in the broad room. For whatever man may do to you, he shall not straiten you; because you love that which man cannot hurt: lovest God, lovest the brotherhood, lovest the law of God, lovest the Church of God: it shall be for ever. Thou laborest here on earth, but you shall come to the promised enjoyment.
Who can take from you that which you love? If no man can take from you that which you love, secure you sleep, or rather secure you watch, lest by sleeping you lose that which you love. For not without reason is it said, “Enlighten my eyes, lest at any time I sleep in death.” They that shut their eyes against charity, fall asleep in the lusts of carnal delights. Be wakeful, therefore. For then are the delights, to eat, to drink, to wanton in luxury, to play, to hunt; these vain pomps all evils follow.
Are we ignorant that they are delights? Who can deny that they delight? But more beloved is the law of God. Cry against such persuaders: “The unrighteous have told me of delights: but not so as is your law, O Lord.” This delight remains. Not only remains as the goal to which you may come, but also calls you back when you flee.
Source: Homilies on the First Epistle of John (New Advent)