Elie Wiesel faced several challenges when he wrote Night.
First, Elie did not really know what he "wanted to achieve" with his words. He only realized that his life would not be what it was without his testimony.
Second, Elie struggled with how to say the things he wished to. He felt that although he "had many things to say," he "did not have the words to say them." He felt that the words which existed were not right. He needed to "invent a new language."
Third, Elie knew that his work would not be received well. Given that the novella deals with a time "from the darkest zone of man," those who have not experienced the life of a persecuted person during the Holocaust will not really know (the pain and reality behind it). Elie only hoped he could help them to understand.
Lastly, Elie found his first edition, one written in Yiddish, to be far too long. He needed to make some revisions in order to provide the necessary "substance" and not the "superfluous" material.