The Hebrews writer having reviewed the superiority of Jesus over everything gives a warning to those who refuse to believe. He gives some examples of those who refused God’s message. Jesus is greater than Moses, Aaron, angels, anything, or anyone (Hebrews 3:5-6). Judgment day is coming. We must remain steadfast in faith.
My translation and notes on Hebrews 12:25-29
Do Not Reject God’s Warning
25 Beware, that youp don’t refuse him who speaks, because if they didn’t escape him who spoke on earth, how much more will we not escape if we turn away from him who [speaks] from heaven.
[The first speaker was God from Mount Sinai. God speaking to Israel gave a command, “If even an animal touches the mountain, it must be killed by stoning or spearing.” The Israelites must obey, or they would die. How terrifying! The second speaker is Jesus, God the Son, and His message found in the Gospels and writings of the Apostles and prophets. We must not turn away from Him, and what He says].
26 His voice shook the world then, but now he has promised, “Yet once more, I [will] shake, not only the earth, but also heaven.” [Exodus 19:18 and Haggai 2:6]
27 Now this quote, “Yet once more,” indicates the removal of shakable things that are made, so that those things which cannot be shaken will stay in place.
[Mount Sinai shook from the power of God, but Mount Zion, the New Jerusalem, cannot be shaken. It is stable, steadfast, and immovable. This is the Kingdom that we are going to live in eternally. Because of this great promise, let us make it a priority to have God’s worldview and lifestyle and to live by His rules bearing much fruit (Galatians 5:22-23) for God’s glory.
28 Therefore, receiving a kingdom that cannot be shaken, let us keep holding on to grace through which we can serve God acceptably with reverence and godly fear,
29 Because our God [is] a consuming fire. [Deuteronomy 4:24]
[Barclay (beware) writes (BARCLAY DAILY STUDY BIBLE): Moses is telling the people that they must never break their agreement with God and relapse into idolatry. For he is a jealous God. They must worship him alone or they will find him a consuming fire. It is as if the writer to the Hebrews was saying: “There is a choice before you. Remain steadfastly true to God, and in the day when the universe is shaken into destruction your relationship with him will stand safe and secure. Be false to him and that very God who might have been your salvation will be to you a consuming fire of destruction.” It is a grim thought; but in it there is the eternal truth that, if a man is true to God, he gains everything and, if he is untrue to God, he loses everything. In time and in eternity nothing really matters save loyalty to God].