Two versions of this מאמר exist:
1) There are three levels of קדושה, two are available to us and the third is not. If we are to reach it, we must become בטל.
They are: תפלה, תורה, מצות.
2) We can reach the third level of קדושה as well.
They are תורה, מצות, and תשובה.
The Rebbe explains the two versions and the timing of each (ספירת העומר and אלול-תשרי).