One mitzvas aseh which the Chafetz Chaim says is kollel all of them which automatically you violate when you speak lashon hara – and is maybe the biggest one – is “אֶת ה’ אֱלֹקֶיךָ תִּירָא”. We have an obligation, a mitzvas aseh d’oraisa, to have an awe of Hashem. The pasuk says tira. Tira doesn’t mean fear, not that Hashem is going to hit me over the head. Tira is the language of awe. I have to be aware of Hashem’s presence, I have to understand the honor and awe due to Hashem and I have to focus on that.
Now, the manifestation of this is particularly if I’m in a nisayon, if I’m in a test. I have to awaken within myself the fear of Hashem. And that fear of Hashem will help me vanquish the desire, will help me vanquish and win the fight. Certainly if I don’t focus on this and I freely speak lashon hara, I violated “אֶת ה’ אֱלֹקֶיךָ תִּירָא”. If I would be cognizant of one reality that Hashem fills every particle of physicality, wherever there’s anything physical Hashem is, that means Hashem is here, if I would be even remotely aware of that obviously I wouldn’t violate Hashem’s wishes. I wouldn’t be speaking lashon hara. The fact that I’m violating Hashem’s ratzon means that I’m denying Hashem’s presence. I’m actively doing the opposite of what the Torah says. The Torah says I should develop and foster an awe of Hashem and what I’m doing is I’m denying Hashem’s presence, I’m actively doing the opposite.
By speaking lashon hara not only am I again violating the various lo sa’asehs and asehs, I’m almost eradicating my recognition of Hashem’s presence. If I just sit there and I don’t focus on it, I’m not necessarily doing anything positive or negative. But if I specifically do something against the will of Hashem, then I’m eradicating that knowledge from my heart, I’m violating “אֶת ה’ אֱלֹקֶיךָ תִּירָא”.