Book II, Admonitions Leading to the Inner Life: 9. Of Lack of Solace and Comfort. (II.9), 87-90.
It is no great thing to despise the comfort of man when the comfort of God is present. But it is a great thing, and indeed a very great thing, that a man should be so strong in spirit as to bear the lack of both comforts, and for the love of God and for God’s honor should have a ready will to bear desolation of spirit and yet in nothing to seek himself or his own merits.
… We are always glad to have solace and consolation, but we desire to have no tribulation, and we will not easily cast forth from ourselves the false love of ourselves. …
[W]hen spiritual comfort is sent to you by God, take it humbly and give thanks meekly for it. But know for certain that it is the great goodness of God that sends it to you, and not because you deserve it. … That time of comfort will pass away, and the time of temptation will follow shortly after.
When comfort is withdrawn, do not be cast down, but humbly and patiently await the visitation of God, for He is able and powerful to give you more grace and more spiritual comfort than you first had. … David said: You have withdrawn your face from me, and I am perturbed. …
… The company of good men and the fellowship of devout brethren and faithful friends, the possession of holy books or of devout treatises, the hearing of sweet songs or of devout hymns may avail little and bring but little comfort to the soul when we are left to our own frailty and poverty. And when we are so left, there is no better remedy than patience, with a complete resignation of our will to the will of God.
I never yet found any religious person so perfect that he did not experience at some times the absence of grace or some diminishing of fervor. … [G]reat consolation is promised by our Lord to those who are found unshaken in their temptation. And therefore the Lord says: To him who overcometh I shall give to eat of the tree of life.