Chapter 14 — Part I: The Creed — Article XII: Life Everlasting
Section 5. "Everlasting" — The supreme happiness of the blessed is called by this name (life everlasting) principally to exclude the notion that it consists in corporeal and transitory things, which cannot be everlasting. The word blessedness is insufficient to express the idea, particularly as there have not been wanting men who, puffed up by the teachings of a vain philosophy, would place the supreme good in sensible things. But these grow old and perish, while supreme happiness is to be terminated by no lapse of time. Nay more, so far is the enjoyment of the goods of this life from conferring real happiness that, on the contrary, he who is captivated by a love of the world is farthest removed from true happiness; for it is written: Love not the world, nor the things which are in the world. If any man love the world, the charity of the Father is not in him, and a little farther on we read: The world passeth away, and the concupiscence thereof.