This verse makes it clear that the signs were to be done so that they might believe that the Lord, the God of their fathers, the God of Abraham, the God of Isaac and the God of Jacob had appeared to Moses. The signs were only necessary because of unbelief and because the people needed to believe Moses’ words in order for him to lead them into their new and scary way of life.
5 “that they may believe that the LORD, the God of their fathers, the God of Abraham, the God of Isaac, and the God of Jacob, has appeared to you.”