I think that any human would have been overwhelmed by the idea of going up against the power of the Egyptian pharaoh. We look at these events through 21st century eyes. Through our faith, and the many great acts that God has performed individually, communally and worldwide Moses has such an intimate relationship, that God was willing to reassure and comfort him, so that he would proceed. I wish that I had the faith Moses had. He gave himself over completely to God, and had conversation with the Almighty for decades. Once he took on the task, he saw it through. He did have a mentor in Jethro, his father in law. Jethro later advises Moses on how to administer justice during the exodus. They undoubtedly had many great conversations of faith in the forty years in Midian.