The point is where the New Jerusalem is located. It is brought down to the New Earth and is the capital city of the New Earth. When I talk about the New Earth I am including the New Jerusalem. However, the New Jerusalem does not include the whole New Earth. For example, when you speak of Oregon, does that include the city of Portland? Yes. But if you speak of Portland, that doesn't include the whole state of Oregon.
Scripture speaks of the New Earth in certain places (II Peter 3:13, Isaiah 65 & 66) without mentioning the New Jerusalem. These scriptures all use the term New Earth without using the term New Jerusalem.
For more information on the subject of Heaven, see Randy Alcorn’s book Heaven.
Randy Alcorn (@randyalcorn) is the author of over sixty books and the founder and director of Eternal Perspective Ministries.