1. As long as we live in this world we cannot be without tribulation and temptation. Hence it is written in Job: "The life of man upon earth is a temptation" - Job 7:1. Therefore ought everyone to be solicitous about his temptations, and to watch in prayer, lest the devil, who never sleeps, but "goeth about seeking whom he may devour" - 1 Peter 5:8. No man is so perfect and holy as not to have sometimes temptations; and we cannot be wholly without them.
2. Yet temptations are often very profitable to a man although they be troublesome and grievous: for in them a man is humbled, purified, and instructed. All the saints have passed through many tribulations and temptations and have profited by them; and they who could not support temptations have became reprobates and fallen away. There is no order so holy, nor place so retired, where there are not temptations and adversities.
3. A man is never entirely secure from temptations as long as he lives; because we have within us the source of temptation, having been born in concupiscence. When one temptation or tribulation is over another comes on; and we shall have always something to suffer, because we have lost the good of our original happiness. Many seek to fly temptations and fall more grievously into them. By flight alone we cannot overcome; but by patience and true humility we are made stronger than our enemies. He who only declines them outwardly and does not pluck out the root will profit little; nay, temptations will sooner return to him, and he will find himself in a worse condition. By degrees, and by patience, with longanimity, thou shalt by God's grace better overcome them than by harshness and thine own importunity. In temptation often take counsel, and deal not roughly with one that is tempted; but comfort him as thou wouldst wish to be done to thyself.
Taken form Book One - Useful Admonishes for a Spiritual Life of "My Imitation of Christ" by Thomas a Kempis. Revised translation edited by Confraternity of the Precious Blood, Imprimatur Thomas Edmundus Molloy, Archbishop of Brooklyn, 1954