28Moses told Aaron all the words of the LORD with which He had sent him, and all the signs that He had commanded him to do.
29Then Moses and Aaron went and assembled all the elders of the sons of Israel;
30and Aaron spoke all the words which the LORD had spoken to Moses He then performed the signs in the sight of the people.
31So the people believed; and when they heard that the LORD was concerned about the sons of Israel and that He had seen their affliction, then they bowed low and worshiped.
Because of their severe oppression, the people of Israel in Egypt were already looking for God to show up. Therefore, when He did come in the form of Moses and Aaron (who also enlisted their leaders as God instructed), they recognized their God, knew He was concerned about them and had seen their affliction. Seeing God show up evoked a strong reaction, they bowed down and worshiped.
There are these powerful times in our lives when we are at the end of ourselves with no hope. Then, finally we look to God to show up and rescue us. When He does show up, all we can do is be humbled and grateful to see tangible evidence that He really is there and He cares. We do have a God who cares more than we can imagine. Part of His caring is bringing us to a place where we have to stop and look to Him because there is no other way. He knows we need these stress points to be made ready for Him and to grow our faith in Him.