Nicene and Post-Nicene Fathers, Ser. II, Vol. XI:
The Works of John Cassian.: Chapter IV. How there is a twofold reason for the permission and allowance of God.

Chapter IV.

How there is a twofold reason for the permission and allowance of God.

But for God’s permission and allowance there is a twofold reason. First, that being for a short time forsaken by the Lord, and observing with all humility the weakness of our own heart, we may not be puffed up on account of the previous purity of heart. granted to us by His visitation; and that by proving that when we are forsaken by Him we cannot possibly recover our former state of purity and delight by any groanings and efforts of our own, we may also learn that our previous gladness of heart resulted not from our own earnestness but from His gift, and that for the present time it must be sought once more from His grace and enlightenment. But a second reason for this allowance, is to prove our perseverance, and steadfastness of mind, and real desires, and to show in us, with what purpose of heart, or earnestness in prayer we seek for the return of the Holy Spirit, when He leaves us, and also in order that when we discover with what efforts we must seek for that spiritual gladness—when once it is lost—and the joy of purity, we may learn to preserve it more carefully, when once it is secured, and to hold it with firmer grasp. For men are generally more careless about keeping whatever they think can be easily replaced.