If your child asked you "How high is heaven?", what would your answer be?

This is a great question! 👍

My son is married already, but if he were 5-years old again, I'd stir up his awe by pointing to a high skyscraper and say, "heaven is higher than that!". After this, I'd point to a plane flying overhead and I'd say, "heaven is higher than that!". Lastly, I'd take him out into the yard during the daytime and point to the moon in the blue sky. Then I'd say, "heaven is higher than that!". As the dad, I'd just stand in pleasure at the reaction of his wonderment. How precious is child-like faith.

As for you and I as adults, we'd have to wade through all our logic and paradigms in order to release ourselves into simple faith and just stand in awe when God, our heavenly Father, through His Word says, "heaven is higher than that!".

Let's see what God says in His Word.

The "waters above the firmament" is the divide between the 3rd heaven (God's throne), and the created heavens (or universe). This divide is mentioned in Genesis, during the creation, and is of interest to understand in more detail in regards to the question at hand.

In the above image I quote Genesis 1:7-8. This scripture explains how God, during creation, made the firmament (the divide), and then divided the waters below it into two parts, the first heaven, which is the atmosphere layer of earth, and the second heaven, which is space, and all the celestial bodies within it. The "waters above the firmament", is the divide between creation and the throne of God. We get the name, "waters above the firmament", from Psalm 148:4.

As with much of scripture and prophecy that has patterns or significance that repeats, this divide is seen not only in the creation of the heavens, but it also appears in repetition in other scripture accounts. The most significant repeat of this pattern is in the design of the tabernacle in the wilderness, and the Jewish temple. In the image below we see the outer courts, then the holy place, then a divide, which in this case was a thick curtain, which separated the Holy of Holies from the Holy Place. The firmament plays the same role in the heavens.

Another reference to this divide, that we find in scripture, is "the crystal sea". This particular "sea" is above the firmament (the known physical universe). It represents a firm and impassable barrier between the world of man (below) and the world of God (above).

John 8:22-23 "Then said the Jews, Will he kill himself? because he saith, Whither I go, ye cannot come. And he said unto them, Ye are from beneath; I am from above [the firmament]: ye are of this world; I am not of this world."

The 3rd Heaven is above this upper "Sea", and this higher sea is below the Throne of God:

Revelation 4:6 "And before the throne there was a sea of glass like unto crystal: and in the midst of the throne, and round about the throne, were four beasts full of eyes before and behind."

As God's child, I stand in awe of His highest heaven and I can see Him smiling at the wonderment of my faith in His Word.