Special preparations require special moments. God Himself was about to have a meeting with His people. God warned the people no to even touch the mountain, nor to touch anyone who had touched the mountain, for the presence of God was so holy. If someone touched the mountain they were to be put to death, and no one was to even touch them in the execution process. They were to be stoned or shot with an arrow so that no connection would be made with their body.
Now all of this might seem a little over the top to you and I, but that is only because we do not understand the extremity of God’s holiness. You and I think of people who seem holy and we take on an idea of what holiness is. But compared to God’s holiness, mother Theresa looks like a vile sinner. We have never experienced this kind of holiness in our short lives.
The amazing thing here is that God was willing to meet with people in spite of this extreme holiness differential. In order to make God happy with us through our actions we would have to achieve this same level of holiness as God has. And, of course, this is impossible. That’s why we rely on the grace of our Lord Jesus, who has made us perfectly holy through His death on the cross!