In Context

26 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."

27 The words "once more" indicate the removing of what can be shaken--that is, created things--so that what cannot be shaken may remain.

28 Therefore, since we are receiving a kingdom that cannot be shaken, let us be thankful, and so worship God acceptably with reverence and awe,

29 for our "God is a consuming fire."

Hebrews 12:29 in Other Translations