In order for Moses to have a chance at getting the Israelites out of Egypt, he had to convince two groups of people. First, and most obviously, he had to talk to Pharaoh. That much was given; the Israelites were still legally his people, after all.
But he also had to convince the Israelites themselves. Even though they were steeped in bondage, there’s a familiarity to one’s state that makes someone hesitant to leave. The status quo is comfortable (even if the status quo is slavery), so Moses would need to meet with the Israelites to gain their support.
So off he went, with Aaron in tow, to speak to the elders of Israel. When he got there, Aaron told them everything that God had spoken to Moses (Exodus 4:5-6). Then, Moses showed the signs that God told him to perform (Exodus 4:3-9). As a result, the people believed (Exodus 4:31).
This shows a very natural and logical progression of faith: hear the word of God and believe the word of God. The signs were given to confirm the authenticity of the messenger, just as spiritual gifts were used in the first century.
But believing in God and worshipping God can be two very different things. Theoretically, the Israelites could be completely convinced that God sent Moses, but worshipping Him as their Deliverer? That takes commitment.
Yet in the New Testament, this is the very definition of faith. Hebrews 11:6 says that faith consists of two parts – the belief that He is, and that He is a rewarder of those who “diligently seek Him.” Faith is not only the understanding that God is real, but also that He will reward a life of faithful obedience to Him.
In an emotional way, you can see this with Exodus 4:31. There, the Text records that “when they heard that the Lord was concerned with the sons of Israel, and that He had seen their affliction, they bowed low and worshipped.” In other words, they acknowledged that God was a God of compassion and worshipped Him as such.
If these Israelites had only maintained this attitude throughout the Exodus, the story might have been a little different. By the time they end up in the wilderness, many of them are clamoring for Egypt. At the doorstep of Canaan, they’ll balk, claiming that God led them out to die.
Faith is not only a belief in the existence of God, but the belief that He keeps His promises. May we never forget that like the Israelites did.