13 Lastly, mark what follows. “Therefore,”— that is, because “I have not found so great faith in Israel,” that is, so great humility with faith—“Therefore I say unto you, that many shall come from the east and west, and shall sit down with Abraham and Isaac and Jacob in the kingdom of heaven.” “Shall sit,” that is, “shall rest.” For we must not form notions of carnal banquets there, or desire any such thing in that kingdom, as to change not vices for virtues, but only to make an exchange of vices.
For it is one thing to desire the kingdom of heaven for the sake of wisdom and life eternal; another, for the sake of earthly felicity, as though there we should have it in more abundant and greater measure. If you think to be rich in that kingdom, you do not cut off, but only changest desire; and yet rich you will really be, and in none other place but there will you be rich; for here your want gathers together the abundance of things. Why have rich men much? Because they want much.
A greater want heaps together as it were greater means; there want itself shall die. Then you shall be truly rich, when you shall be in want of nothing. For now you are not surely rich, and an Angel poor, who has not horses, and carriages, and servants. Why? Because he does not want any of these: because in proportion to his greater strength, is his want the less. Therefore there there are riches, and the true riches. Figure not to yourselves then banquets of this earth in that place.
For the banquets of this world are daily medicines; they are necessary for a kind of sickness we have, wherewith we are born. This sickness every one is sensible of, when the hour for refreshment is passed. Would you see how great a sickness this is, that as an acute fever would be fatal in seven days? Do not fancy yourself then to be in health. Immortality will be health. For this present is only one long sickness. Because you support your disease by daily medicines; you fancy yourself in health; take away the medicines, and then see what you can do.
Source: Sermons on Selected Lessons of the New Testament (New Advent)