Small tidbits and Sparks of wisdom

There are two levels of fear in serving Hashem. The first is fear of punishment — a person avoids sin because he fears suffering in this world or the next. This fear is natural, since every person protects himself from harm. Just as people avoid poison because they fear its consequences, so too fear of punishment distances a person from sin.
Rabbi Miller Commentary:
This does not mean fear of punishment is only for simple people. Even great tzaddikim feared punishment. The mistake is thinking that a wise person no longer fears consequences. Rather, the deficiency is when punishment is the only motivation.
Fear of Hashem’s Greatness
Mesillas Yesharim:
The higher level is יראת הרוממות — fear of Hashem’s exaltedness. A person avoids sin not because of punishment, but because he realizes he stands before the King of kings. Just as someone standing before a human king would naturally restrain himself out of respect, so too one who feels Hashem’s presence is ashamed to rebel against His will.
Rabbi Miller Commentary:
This level is not easily acquired. It comes through wisdom, contemplation, and humility — thinking deeply about the greatness of Hashem and the smallness of man. When a person truly reflects on creation, nature, and Hashem’s infinite wisdom, arrogance weakens and genuine yirah begins.