Only with Hashem's Help
Depending on Hashem to withstand a test.
Rav Yisroel Salanter used to say that he wouldn't trust himself to be in a room with an uncounted box of money unless there were people constantly going in and out.
R' Yeruchum said that with his own self-knowledge, he wouldn't trust himself even with money that HAD been previously counted!
When we go through a day without doing an aveirah, as well as praising and congratulating ourselves, we should realize that it's a wonderful favour and chessed from Hashem, and if we think it's all because of us, we're mistaken.
Even these great gedolim were fully aware that there is not a chance of beating the yetzer harah through our own means. It is only with the help of Hashem- every single time- that we can pull through.
Next time you feel you overcome with the temptation to sin, offer a small thanks to Hashem who gave you the strength to overcome. He believes in you, so should you!