I remember reading about a monk in the Sayings of the Desert Fathers
who struggled with an unspecified temptatious thought for many years and prayed earnestly each day for it to be taken away from him. Eventually God took the temptation away from the monk. But the monk then became very bored and prayed for God to give him his temptation back. Henceforth the monk prayed not that the temptation might be taken away from him but that he would have enough strength not to succumb to it.
I found the following apothegmata involving Abba Poemen and Abba John the Dwarf that is very similar to the above story but I'm sure that there is another one. Does anyone know what it is?
Abba Poemen said of Abba John the Dwarf that he had prayed God to take his passions away from him so that he might become free from care. He went and told an old man this; 'I find myself in peace, without an enemy,' he said. The old man said to him, 'Go beseech God to stir up warfare so that you may regain the affliction and humility that you used to have, for it is by warfare that the soul makes progress.' So he besought God and when warfare came, he no longer prayed that it might be taken away, but said, 'Lord, give me strength for the fight.'
Peace of Xrist,