That the scriptures teach that there is a heavenly, spiritual and invisible realm (invisible to us) cannot be denied.
But when was this realm made? It was created by God in the beginning.
When were the angels made who reside there? They were created by God in the beginning.
“In the beginning, God created the heavensand the earth.” (Genesis 1:1, ESV)
This is confirmed by the Apostle Paul. When he wrote concerning the creation he said, “For by him [that is Christ, the eternal Word of God come in the flesh] all things were created, in heaven and on earth, visible and invisible,whether thrones or dominions or rulers or authorities—all things were created through him and for him. And he is before all things, and in him all things hold together” (Colossians 1:16–17, ESV). Paul interprets heaven as the spiritual realm that is invisible to us, and earth as the physical realm that does correspond to our natural senses.
Consider also how God’s creation of heaven and earth are spoken of in Nehemiah 9:6. There the people give praise to God, saying, “You are the Lord, you alone. You have made heaven, the heaven of heavens, with all their host, the earth and all that is on it, the seas and all that is in them; and you preserve all of them; and the host of heaven worships you” (Nehemiah 9:6, ESV). Do you hear it? Clearly Nehemiah 9:6 interprets “heaven” of Genesis 1:1 as being the “heaven of heavens”. It is the place where the host, or army, of heaven dwells. That is to say, the angels. They are the ones who worship and serve God forever and ever.
And also consider that Job 38 teaches that the angles of God were present to witness the creation of the world from their heavenly vantage point. It is here in this passage that God questions Job, saying, “Where were you when I laid the foundation of the earth? Tell me, if you have understanding. Who determined its measurements—surely you know! Or who stretched the line upon it? On what were its bases sunk, or who laid its cornerstone, when the morning stars sang together and all the sons of God shouted for joy?” (Job 38:4–7, ESV). God is here speaking of the creation, or formation of the earth. And he asks Job, “Where were you” when I did all of this? God was reminding Job that he was God the Creator, and that Job was but a creature. Job was not there to witness the formation of the earth. Indeed, no man was there. Man would not be created until the sixth day, as we will see. But who was there to see? Of course God was there! But so too were there angels. “The morning stars sang together and all the sons of God shouted for joy”, when they witness God’s act of creation.
What did God do in the beginning? He created the heavenly realm, and also the earthly realm. This is why in Isaiah 37:16 God is called the “Lord of hosts [and the] God of Israel, enthroned above the cherubim, you are the God, you alone, of all the kingdoms of the earth; you have made heaven and earth” (Isaiah 37:16)