Hebrews 12:25-29 "See to it that you do not refuse him who speaks. If they did not escape when they refused him who warned them on earth, how much less will we, if we turn away from him who warns us from heaven? At that time his voice shook the earth, but now he has promised, "Once more I will shake not only the earth but also the heavens." The words "once more" indicate the removing of what can be shaken—that is, created things—so that what cannot be shaken may remain. Therefore, since we are receiving a kingdom that cannot be shaken, let us be thankful, and so worship God acceptably with reverence and awe, for our "God is a consuming fire."
Moses relayed the law to the people. He was the one who warned the people on earth and those who refused to obey did not escape. Jesus is the one who warns from Heaven and the author says if the punishment is so severe for breaking the law; know that it will be much more severe for not listening to Jesus!
We are actually under a double responsibility. Those back under the law only knew part of the truth. Because of Jesus, we know God’s full truth and should have no excuse for not obeying Him. It’s like the saying, “To who much is given, much is expected.”
When the first law was given, the world shook!
(Exodus 19:18) (Psalm 114:7) (Psalm 68:8) (Psalm 77:18)
The author says, someday the world will shake again. Everything that can be uprooted will be destroyed. The only things that will remain will be what can’t be shaken: our relationship with God. Jesus spoke in Matthew about the importance of building on a firm foundation.
We must worship God with reverence. We must serve Him with fear. The author ends this passage by quoting Deuteronomy 4:24 “For the LORD your God is a consuming fire, a jealous God.”
Moses told the Israelite this, but it’s true for us too. God must be first in our lives. Having a relationship with Him, being able to approach Him now, doesn’t change that. If we put God first and our faith remains unshakable – when the end comes, whether Christ comes back in our lifetime, or we die of old age - we will be safe and secure. We have a choice!