If the yetzer hara tells you to commit an aveirah, think: “Perhaps Hashem is testing me now as He tested Avraham Avinu. Perhaps this is one of the key tests of my life.”  

When a person knows he is being tested, he will be very vigilant and pass the test. Think such thoughts…because Hakadosh Baruch Hu sends challenges to test people. Fortunate is the person who always thinks about Hashem.

~ The Shlah