18 All the people perceived the thunder and the lightning flashes and the sound of the trumpet and the mountain smoking; and when the people saw it, they trembled and stood at a distance. 19 Then they said to Moses, “Speak to us yourself and we will listen; but let not God speak to us, or we will die.” 20 Moses said to the people, “Do not be afraid; for God has come in order to test you, and in order that the fear of Him may remain with you, so that you may not sin.” 21 So the people stood at a distance, while Moses approached the thick cloud where God was.
22 Then the LORD said to Moses, “Thus you shall say to the sons of Israel, `You yourselves have seen that I have spoken to you from heaven. 23 `You shall not make other gods besides Me; gods of silver or gods of gold, you shall not make for yourselves. 24 `You shall make an altar of earth for Me, and you shall sacrifice on it your burnt offerings and your peace offerings, your sheep and your oxen; in every place where I cause My name to be remembered, I will come to you and bless you. 25 `If you make an altar of stone for Me, you shall not build it of cut stones, for if you wield your tool on it, you will profane it. 26 `And you shall not go up by steps to My altar, so that your nakedness will not be exposed on it.’
In everything we do, God wants to be glorified. Here, even if the Israelites were to make an altar, it was to be all natural. Or, in other words, just as God created it. They couldn’t try to make the rocks look all fancy. They couldn’t use fancy materials. Their options were earth and uncut stone. In our lives, God doesn’t want us to be puffed up with the ‘amazing’ things we’ve done for Him. He wants all the credit for that. He created us, after all, so it’s only fair. But more than that, we should want to glorify Him in everything we do. That should be our guiding purpose: to glorify Him.