The words "once more" indicate the removing of what can be shaken - that is, created things - so that what cannot be shaken may remain. (Hebrews 12:26-27)
The pivotal word in this passage of scripture starts with a 'p'... "promised." This shake, rattle, and roll is God's promise to all the earth.
How we love the promises of God that include health, prosperity, and blessing. How we dread the promises of God that involve shaking, persecution, and tribulation.
John 16:33 "I have said these things to you, that in me you may have peace. In the world you will have tribulation."
John 15:20 "If they persecuted me, they will persecute you also."
James 1:2 "Count it all joy, my brothers, WHEN you meet trials of various kinds..."
Along with tribulation, persecution, and trials, God also promises shaking!
It's not the political or socioeconomic world that God is shaking. It is the world within, our personal world. Just as the Kingdom is WITHIN us, God desires to shake everything in our personal worlds so that ALL that supports the KINGDOM remains, while all that doesn't, falls by the wayside.
When God said, "yet once more I will shake not only the earth but the heavens," He was referring to a time of severe physical and spiritual testing for the believer.
No longer is God Mr. Hercules, graciously supporting your world upon His broad, Herculean shoulders. He is Hercules, shaking the earth between His massive hands until everything that can broken, will be broken. Only that which can't be broken, will remain afterwards.
We are not so confident of the friendships and family ties we've invested so heavily in, during this shake. We are not so confident of our well-honed abilites during this shake. We are not so confident of the scriptures we quoted and the prayers we've prayed, during this shake. We are not so confident of anything at all during this shake.
But God is still amazingly confident. While He watches how we lose ALL of our confidence, He remains giddily sauve. Why? He knows this one Truth: only the things TRULY FORMED by God will be able to stand the tests of God. God's building blocks are earthquake-proof. It will remain intact when all is finished rattling.
But the intricately devised, intelligently conceived concepts of church doctrine and religious thought - all of these things WILL BE shaken and DESTROYED in the shaking.
God desires TRUTH in the inmost parts (Ps 51:6)
Being a 21st century Christian is not that different from being a 1st century Pharisee. There is truth intertwined with a lot of religious thought passed down from generations of church doctrines, subtley tweaked by a long chain of important figures in church history. Inspite of all this, God is still trying to reach His people today. He promises to reach them through severe shakings!
Will your faith survive in the end???
Perhaps like Job after his shake, we will also say, "My ears had heard of you but now my eyes have seen you...therefore I despise myself and repent in dust and ashes...(Job 42:5-6) That will be a blessed day indeed, because when God shows up at the end of the storm, we can finally know Truth.