“It is characteristic of God and his angels to bring to the soul, when they occupy it, true happiness and spiritual joy; and to drive from it the sadness and trials which the enemy incites in it.” St. Ignatius of Loyola

‘At the start of the spiritual way, the soul usually has the conscious experience of being illumined with its own light through the action of grace. But, as it advances further in its struggle to attain theology, grace works its mysteries within the soul for the most part without its knowledge. Grace acts in these two ways so that it may first set us rejoicing on the path of contemplation, calling us from ignorance to spiritual knowledge, and so that in the midst of our struggle it may then keep this knowledge free from arrogance. On the one hand, we need to be somewhat saddened by feeling ourselves abandoned, so that we become more humble and submit to the glory of the Lord; on the other hand, we need to be gladdened at the right time through being lifted up by hope. For just as great sadness brings the soul to despair and loss of faith, so great joy incites it to presumption (I am speaking of those who are still beginners). Midway between illumination and abandonment lies the experience of trial, and midway between sadness and joy lies hope. This is why the Psalmist says: ‘I waited patiently for the Lord; and He heard me’ (Ps. 40: 1); and again: ‘According to the multitude of the sufferings in my heart, Thy blessings have gladdened my soul’ (Ps. 94:19. LXX).’
St. Diadochos of Photiki

When God recedes in order to educate us, this brings great sadness, humility and even some measure of despair to the soul. The purpose of this is to humble the soul’s tendency to vanity and self-glory, for the heart at once is filled with fear of God, tears of thankfulness, and great longing for the beauty of silence. But the receding due to God’s complete withdrawal fills the soul with despair, unbelief, anger and pride. We who have experienced both kinds of receding should approach God in each case in the appro­priate way. In the first case we should offer Him thanks as we plead in our own defense, understanding that He is disciplining our unruly character by concealing His presence, so as to teach us, like a good father, the difference between virtue and vice. In the second case, we should offer Him ceaseless confession of our sins and incessant tears, and practice a greater seclusion from the world, so that by adding to our labors we may eventually induce Him to reveal His presence in our hearts as before. Yet we must realize that when there is a direct struggle between Satan and the soul – and I am speaking here of the struggle that takes place when God recedes in order to educate us – then grace conceals itself a little, as I have said, but nevertheless supports the soul in a hidden way, so that in the eyes of its enemies the victory appears to be due to the soul alone.’
St. Diadochos of Photi

There is another kind of sadness as well, which is more detestable. It inspires in the wrongdoer not amendment of life or correction of vice but the most pernicious despair of soul. It did not cause Cain to repent after his brother’s murder or Judas to hasten to healing and reparation after the betrayal; instead it drew him to hang himself with a noose of despair.

Hence sadness is to be judged beneficial for us in one instance alone — when we concieve it out of repentance for our sins and are inflamed by a desire for perfection, and by the contemplation of future blessedness.

Of this the blessed Apostle himself says: “The sadness that is in accordance with God works repentance unto a lasting salvation, but the world’s sadness works to death.”

The sadness that “works repentance unto a lasting salvation,” likewise, is obedient, courteous, humble, mild, gracious, and patient, inasmuch as it comes from the love of God. It stretches itself out tirelessly, in its desire for perfection, to every bodily pain and to contrition of spirit.

With a kind of joy, and quickened by the hope of its own progress, it retains all its gracious courtesy and forbearance, having in itself all the fruits of the Holy Spirit, which the same Apostle enumerates: “The fruits of the Spirit are love, joy, peace, forbearance, goodness, kindness, faith, mildness, continence”. [Galatians 5:22-23]

But the other is very harsh, impatient, rough, full of rancor and barren grief and punishing despair, crushing the one whom it has embraced and drawing him away from any effort and from salutary sorrow, since it is irrational. Too, it not only removes the efficacy of prayer but also eliminates all the spiritual fruits that we have spoken of and that the first is capable of bestowing.’
St. John Cassian