I was talking with a brother struggling with sin once. He told me he had managed to resist temptation the night before. "Good!" I said. "But whether you gave in or not, are you still able, looking beyond yourself, to rejoice in Christ's perfect obedience on your behalf?" He hung his head. That was a more difficult question--even more difficult than resisting temptation.
If a Christian resists temptation and then focuses on their victory, is pleased with it, and the joy of it carries them onward--that may be a defeat at a deeper level.