[but] during these final days He has spoken to us through His Son [Note: This period refers to the Christian age (See Acts 2:14-36)], whom He appointed to be heir of all things [and] through whom He created the universe. [See John 1:3; Col. 1:16].

By [having] faith, we understand that the universe was formed by God's word [See Gen. 1:1-27], so that what is seen has not been made out of what is visible.

Now the words, "once more" indicate the removing of what can be shaken --- that is, the created universe --- so that those things which cannot be shaken will remain. [Note: These "things" have been variously interpreted to be eternal truth, the heavenly kingdom, the new heavens and earth, etc.].