Imitation of Christ

Nunquam inveni aliquem Religiosum, qui non habuerit interdum gratiæ subtractionem, aut non senserit fervoris diminutionem. Nullus Sanctus fuit tam alte raptus, vel illuminatus, qui prius vel postea non fuerit tentatus. Non enim alta Dei contemplatione dignus est, qui pro Deo non est exercitatus aliqua tribulatione. Solet enim sequentis consolationis tribulatio præcedens esse signum. Nam tentationibus probatis cælestis promittitur consolatio. Qui vicerit, inquit, dabo ei edere de ligno vitæ.

I have never found any man so religious and godly, but that he felt sometimes a withdrawal of the divine favour, and lack of fervour. No saint was ever so filled with rapture, so enlightened, but that sooner or later he was tempted. For he is not worthy of the great vision of God, who, for God's sake, has not been exercised by some temptation. For temptation is wont to go before as a sign of the comfort which shall follow, and heavenly comfort is promised to those who are proved by temptation. As it is written, To him that overcomes I will give to eat of the tree of life.

Imitation of Christ, II, 9:7