What is the motivation behind Eliezer refusing to pray altogether?
I edited down the original question. I would suggest that Eliezer's motivation behind his refusal to pray is reflective of how his faith in the divine eroded as a result of his time in the camps. Wiesel suggests that one of the real terrors of the Holocaust was how the dehumanization of the Nazi victims rendered them without hope and without faith in the divine. For Eliezer, the transition from who he was at the start of the narrative in terms of religious identity to who he is over the course of the narrative in relationship to how he views God is significant. In Chapter 5, Eliezer refuses to pray because he feels God has forgotten him. Eliezer is open about the fact that he feels God has abandoned so many who cry out to him and yearn for him. God remains silent. When Eliezer witnesses a small boy being executed, struggling for about half an hour in the noose, Eliezer hears someone says "God is on the gallows." It is reflective of how Eliezer has come to see God, as a force whose notion of "absolute justice" has to be questioned with what is seen and experienced during the Holocaust. It is here where one can see the motivation behind Eliezer refusing to pray altogether. Eliezer's questioning of God, of the notion of a merciful divine force becomes the central issue arising from what he sees and experiences during the Holocaust.