Faith in Hashem is the cornerstone of everything. For one who believes in Hashem — Whose Glory fills the earth, and whose eyes are open to all the ways of mankind, to grant each man according to his ways and the consequences of his deeds (Yirmiyah 32:19) — will live by his faith since he will certainly heed all the commandments with all their details. Such a person does mitzvos with alacrity and is careful to remain clean of all sin; he rises like a lion to serve his Creator and he is not intimidated by anyone, because it is so clear to him that the Name of Hashem is upon him and that His eyes see everything. He knows that there is a watchful Eye and an attentive Ear above and that all his deeds are recorded in a Book (see Avos 2:1). He feels shame before Him and serves Him completely, with awe and love and great joy; he believes with perfect faith that there is good reward for the righteous, in accord with how much he does, and that the greater the effort the greater the reward. He knows, too, that there is harsh and bitter punishment for the wicked for every sin and that the scales of justice are in the hands of Hashem to give each person what he deserves — in accord with the person’s ways; in accord with his stature, intelligence and abilities; and in accord with his effort and joy in fulfilling the mitzvos.
ל׳ בניסן ה׳תש״פ
My brother and my nation, take this Torah book, in this and like this learn well, listen and revival your soul, you will achieve joy and joy, in this world and next world. (from introduction of the author) 1