Hebrews 12:28-29
In the verses just before ours, the writer who is writing this letter was talking about listening to God’s voice. He was warning them because the people of Israel caused themselves a lot of trouble all of the times they did not listen to Moses and God.
Exactly 2 months after the Israelites left Egypt, God met them at Mount Sinai. (Exodus 19 & 20) God promised to shake the earth and Heaven at some point. Verse 27 says all creation will be shaken and removed, so that unshakable things will remain.
Our verses are reminding us to be thankful for God’s unshakable Kingdom. NOTHING is greater than God. And while we call Satan “the enemy”, the truth is, he is NOT God’s equal. He, himself, was created BY God. God sent him here to get him out of Heaven because he was prideful and wanted to be the God of everything. This earth and his reign are shakeable! They aren’t really permanent. God’s Kingdom is.
God’s Kingdom might not be seen with the physical eye by everyone, but it’s there. We will see and fully understand one day.