Moussar sur Les Psaumes 118:22

Faith - Faith, “it became the cornerstone” [Psalms 118:22]. For the one who has faith in Hashem, whose glory fills the whole Earth, and whose eyes are open upon all the ways of human beings, to repay each person according to his ways and according to the fruit of his deeds. A righteous person shall live through his faithfulness, because certainly he will be careful in the fulfillment of all the commandments and their precise details. And he should be eager in [performing] the commandments, and careful to be clean from every sin, and exert himself like a lion for the service of his Creator, and not back down in the face of anything. For his eyes will see, and his heart will understand, that the name of Hashem is called upon him, and His eyes range about the whole Earth. An eye sees, an ear hears, and all his deeds are recorded in a book [Avot 2:1]. And he should feel ashamed before him, and serve Him with a perfect service — with fear, love, and great joy. And he will believe with complete faith that there is a good reward for the righteous, according to the greatness of the deed, and according to the difficulty is the reward [Avot 5:23]. And the punishment for the wicked is severe and bitter, over all of their transgressions, and a balance and scales of justice are in the hand of Hashem, to repay each person according to his ways — according to his level, understanding, and ability, and according to the effort and the joy, as two battle lines are set opposite one another.