A quote from Saint Barsanouphius:
Just as one assays the quality of gold or silver in a furnace, so also the souls of men are tested through temptations. Therefore, before you set out to endure temptation, do not overestimate your strength; when temptation does come, you will thus realize what you are capable of enduring. If, at the moment of temptation, you see yourself falling, call at once on the help of God; and the Lord will assuredly deliver you. Resist sin steadfastly, and do not fear the presence of temptation. A brave athlete is not harmed by taking part in a contest; on the contrary, this very experience renders him more proven.