By the love which the saints show unto God in return for what they bear for the sake of His name in that they undergo trials without leaving the excellency which God loves, their heart acquires freedom to look towards Him without a veil and to ask from Him with confidence.

Great is the power of prayer in freedom of speech. Therefore He allows that His saints are tried by all afflictions on the way towards Him in order that they may acquire freedom of speech and may experience His help and His care for them in that He is found to be their saviour in danger; and in order that His friends may acquire wisdom through temptations so that they are not dull and destitute of training. So through temptation they acquire knowledge concerning everything, and are not laughed at lightly by the demons.

For if He would train them by good things only they would lack training in other things and they would be as blind men in trials. And if someone should say : He guides them without training and without self-knowledge [the conclusion would be] that He wished them to be like oxen and asses who possess no freedom whatever. There is even no taste in the good, when a man has not first been tried by temptations of evil and afterwards finds it and when he does not use it as, his own, in knowledge and freedom. How sweet that knowledge is which has been acquired through training and the experience of labours, and how much strength it imparts to him that has found it after many personal experiences, is known to those who are acquainted with the help afforded by it.

They learn the weakness of nature and the help afforded by divine power when He first withdraws power from them while they are in temptations. Then they perceive the weakness of nature and the strength of temptations and the wickedness of the Fiend, [perceiving] of which nature their Fiend is, with which nature they are clad, and how they are guarded by divine power; and how, though they run and are uplifted, when the divine power withdraws itself from them, they become weak before all passions.

Through all this they acquire humbleness, and press close to God, expecting His help and persevering in prayer. How could they have acquired all this, if they had not experienced a myriad of evils, without God's caring for their being surrounded by them 'And lest I should be exalted through the abundance of revelations, there was given me a thorn the flesh, the messenger of Satan' (2 Cor. 12,7)

Man acquires also a confirmed faith by temptations, through experiencing divine help, when it is granted several times. And furthermore he is without fear and acquires courage by temptation, on account of the training he acquires.

Temptation is useful to every man. The virtuous are tempted in order that their riches may increase ; the lax, in order that they may be preserved from injuries ; the sleepy, in order that they may be armed with alertness; those that are afar off that they may come nearer to God ; the members of the household, that they may approach with freedom of speech.

A son that is not trained, cannot profit by the riches that are given to him from his father's house. Therefore God tempts and vexes first, then He shows His gift. Glory to that Lord who by strong drugs brings us the delight of health. There is no one, to whom the time of exercise is, not hard and there is no one, to whom the time during which he is obliged to drink the potion of temptations, is not bitter. But without this, a sound constitution cannot be obtained. Even to endure not of our own. How should a clay vessel endure the vehemence of the waters, if the divine fire had not hardened it? If we deign to ask in humbleness fervently and perseveringly, we shall receive everything.
(taken from the Ascetic Treatises of Saint Issac the Syrian)

The following excerpt has been taken from the life of Saint Anthony the Great for an illustration of steadfastness in temptation and God's ready help for those who endure:

....Having thus mastered himself, Anthony departed to the tombs that lay far from the village, having asked one of his acquaintance to bring him bread from time to time. He entered one of the tombs, his friend closed the door of it on him, and he remained alone within. This the enemy would not endure, for he feared lest by degrees Anthony should fill the desert too with monks; and coming one night with a throng of demons, he so scourged him that he lay on the ground speechless from the pain. For, he declared, the pain was so severe that blows from men could not have caused such agony. By God's providence (for the Lord does not overlook those who hope in Him) his friend came the next day bringing him bread, and when he opened the door and saw him lying on the ground, as dead, he lifted him and took him to the village church and laid him on the ground. Many of his kin, and the village people, watched beside Anthony as for one dead. But towards midnight Anthony came to himself and woke, and seeing all asleep and only his friend waking, he signed to him to come near, and asked him to lift him again and carry him back to the tombs without waking anyone.

So he was carried back by the man, and the door was closed as before, and he was again alone within. He could not stand because of the blows, but he prayed lying down. And after his prayer he shouted out, "Here am I, Anthony! I do not run from your blows! For though you should give me yet more, nothing shall separate me from the love of Christ!" (Rom. 8:35). Then he sang the psalm "Though a host should array itself against me, my heart shall not fear." (Psalm 26:3).

The monk, then, thought and spoke thus. But the enemy of all good, marveling that even after the blows he had courage to go back, called together his hounds and burst out in fury, "Do you see that we have stopped this man neither by the spirit of fornication or by blows, but he challenges us; let us attack him another way." For plans of ill are easy to the devil.

Thereupon in the night they made such a crashing that it seemed the whole place was shaken by an earthquake; and as if they had broken through the four walls of the building, the demons seemed to rush in through them in the guise of beasts and creeping things, and the place was at once filled with the forms of lions, bears, leopards, bulls, serpents, asps, scorpions, wolves. And each moved according to to its own likeness. The lion roared, ready to spring, the bull seemed to be thrusting with its horns, the serpent crept yet reached him not, the wolf held itself in act to strike. And the noise of all the visions was terrible, and their fury cruel.

Anthony, beaten and goaded by them, felt keener bodily pain. Nevertheless he lay fearless and more alert in spirit. He groaned with the soreness of his body, but in mind he was cool, and said jestingly, "If you had any power in you, it would have been enough that just one of you should come; but the Lord has taken your strength away, and that is why you try to frighten me if possible by your numbers. It is a sign of your helplessness that you have taken the shapes of brutes." Again he said cheerily, " If you can, and if you have received power over me, do not wait, but lay on. But if you cannot, why are you chafing yourselves for nothing? For our trust in the Lord is like a seal to us, and like a wall of safety."

So after making many attempts they gnashed their teeth at him because they were befooling themselves and not him.

And the Lord in this also forgot not Anthony's wrestling, but came to his defense.For looking up he saw as it were the roof opening and a beam of light coming down to him. And the demons suddenly disappeared, and the soreness of his body ceased at once, and the building was again sound.

Anthony, seeing that help was come, breathed more freely, being eased of his pains. And he asked the vision, "Where wert thou? Why didst thou not show thyself from the beginning, to end my suffering? And a voice came to him: "I was here, Anthony, but I waited to see thy resistance. Therefore since thou hast endured and not yielded, I will always be thy helper, and I will make thee renowned everywhere." Hearing this he arose and prayed, and he was so strengthened that he perceived that he had more power in his body than formerly. He was at this time about thirty-five years old....

May our Lord through the prayers of Sts. Anthony and Issac grant us courage and confidence in our temptations, that he will not leave us to be a "prey for their teeth".