הַלְלוּהוּ כְּרֹב גֻּדְלוֹ
Praise Him as befits His greatness (Tehillim 150:2)
Sitting in the Kloiz in Uman last Erev Rosh Hashanah at 3:30 am, I suddenly broke out in tears before Selichos even began. Crying oceans of tears, I had an overwhelming feeling of the greatness of Hashem. How was it possible for me to serve Hashem according to His greatness? He is so big, and I am so insignificant in comparison. Pulling myself back together, I was comforted in the thought that Hashem, in His supreme compassion, regarded the little things that I did - such as saying Selichos - as my service of Him. At that moment, I first began to have an understanding of the extent of Hashem’s love for me.
No man serves Hashem according to His greatness. If you have some conception of Hashem’s greatness, you will not understand how one can claim to serve Him. The highest angel cannot say that he truly serves Hashem. (Sichos HaRan #51)