This coming week's Parsha, Emor, has the positive commandment of Kiddush Hashem and the negative commandment of Chilul Hashem, against desecrating the name of G-d.
Obviously these two commandments are extremely important and needs some explanation.
The Rambam views Chilul Hashem as the most severe sin and the most difficult to atone for. Only one's death brings full atonement because a Chilul Hashem can make Hashem look bad.
It should be our goal to sanctify G-d's name in all that we do.
The classic example brought in the Talmud describes the ultimate Chilul Hashem and Kiddush Hashem. If one studies Torah and serves Torah scholars, but his business practices are corrupt, and he does not speak kindly to people, what is said of such an individual? Woe to his father and teachers who taught him Torah. See how corrupt are his ways. This epitomizes Chilul Hashem.
But one who does the reverse and is honest and treats people properly, of him it is said that Hashem is glorified through him. He is a walking Kiddush Hashem. We must strive to sanctify Hashem's name in all that we do.
Yesterday was 29 with ספירת העומר