17 And lead us not into temptation, O Lord. Is this then what the Lord teaches us to pray, that we may not be tempted at all? How then is it said elsewhere, “a man untempted, is a man unproved;” and again, My brethren, count it all joy when you fall into various temptations? But does perchance the entering into temptation mean the being overwhelmed by the temptation? For temptation is, as it were, like a winter torrent difficult to cross. Those therefore who are not overwhelmed in temptations, pass through, showing themselves excellent swimmers, and not being swept away by them at all; while those who are not such, enter into them and are overwhelmed.
As for example, Judas having entered into the temptation of the love of money, swam not through it, but was overwhelmed and was strangled both in body and spirit. Peter entered into the temptation of the denial; but having entered, he was not overwhelmed by it, but manfully swam through it, and was delivered from the temptation. Listen again, in another place, to a company of unscathed saints, giving thanks for deliverance from temptation, You, O God hast proved us; You have tried us by fire like as silver is tried.
You brought us into the net; You layed afflictions upon our loins. You have caused men to ride over our heads; we went through fire and water; and you brought us out into a place of rest. You see them speaking boldly in regard to their having passed through and not been pierced. But You brought us out into a place of rest; now their coming into a place of rest is their being delivered from temptation.
Source: Catechetical Lectures (New Advent)