The Confessions And Letters Of St by St. Augustine
Chapter XXII.--A Happy Life is to Rejoice in God, and for God.
32. Let it be far, O Lord, -- let it be far from the heart of Thy servant who confesseth unto Thee; let it be far from me to think myself happy, be the joy what it may. For there is a joy which is not granted to the |wicked,| but to those who worship Thee thankfully, whose joy Thou Thyself art. And the happy life is this, -- to rejoice unto Thee, in Thee, and for Thee; this it is, and there is no other. But those who think there is another follow after another joy, and that not the true one. Their will, however, is not turned away from some shadow of joy.