It is impossible to draw near to God without sorrows, without which human righteousness cannot remain unchanged... If you desire virtue, than give yourself to every affliction, for afflictions produce humility. If someone abides in virtue without afflictions, the door of pride is opened to him.
Isaac of NinevehThere is no man who will not be grieved at the time of his chastisement; and there is not man who will not endure a bitter time, when he must drink the poison of temptations. Without them, it is not possible to obtain a strong will. When he has often experienced the help of God in temptations, a man also obtains strong faith.
Isaac of NinevehWithout temptations, it is not possible to learn the wisdom of the Spirit. It is not possible that Divine love be strengthened in your soul. Before temptations, a man prays to God as a stranger. When temptations are allowed to come by the love of God, and he does not give in to them, then he stands before God as a sincere friend. For in fulfilling the will of God, he has made war on the enemy of God and conquered him.
Isaac of Nineveh