Genesis 1:1 says, "In the beginning God created the heaven and the earth." In the beginning of what? It obviously does not mean that God had a beginning, for the Word tells us God had no beginning (Deuteronomy 33:27; Romans 1:20; 1 Timothy 1:17; etc.).That is one way that God is different from His creation, in that He is eternal. God could have just as well said, "I WAS, and I AM, and I WILL ALWAYS BE." That is one of the reasons many students of God's Word believe that Melchizedek was a pre-incarnate appearance of Jesus Christ, the Second Person of the Trinity or the Godhead (Romans 1:20; Colossians 2:9). Not only was He a priest, but He was the king of Salem (Hebrews 7:1-3). It is also telling that He gave Abraham bread and wine, and Melchizedek accepted tithes from him (Genesis 14:17-24). If Melchizedek had no beginning, He was obviously not merely a man, for man was created on the sixth day of creation (Genesis 1:26-31). And, last but not least, the Holy Spirit Who is the Third Person of the Trinity, is God and eternal (Acts 5:3-4; Hebrews 9:14).
Everything apart from God had to be created, and therefore, it must be concluded that "the beginning" is the beginning of time. An obvious question arises in that Genesis One does not tell us when the angels were created. Since they are not eternal, nor are they listed in the creation account, most assume angels were created before time began (Isaiah 14:52; Ezekiel 28:13-17; Luke 10:18; 1 John 3:8; Revelation 12:7-9). Job 38:4-7 speaks of the "morning stars" and the "sons of God" being present during our creation. These titles refer to angels (Job 1:6 - 2:7). Also, as can be seen from 1 John 3:8, Satan was already in rebellion when "the beginning" occurred. The fact that they were created to minister to man suggests that they may have been created just prior to the "the beginning" (Hebrews 1:14).
What about heaven itself? Did God have a throne that was eternal? Did Jesus sit at His Father's right hand before creation? (John 17:5; Romans 8:34; Ephesians 1:20; Colossians 3:1; Hebrews 1:13; 8:1; 10:12; 12:2; 1 Peter 3:22). I do not know the answer, but I have a theory. I believe that before there was anything, including the heavenly throne room of God, there was only God. In order for Him to create light other than Himself, He had to create darkness by restricting Himself to a separate place. Then He could create light. He chose to create a place called heaven (the third heaven - 2 Corinthians 12:2). On the first day of creation, God created the heaven well understand to be the universe. And on the second day, He created the heaven we understand as our atmosphere (Genesis 1:1; 1:6-8). So Chronologically, the three heavens were created third, second, and first. It is odd, but it makes sense when one considers that man would exist in them chronologically, that is, flight, space travel, and hopefully all my readers will dwell in the heaven of our great God!
So, what was there before anything else existed? God says, "I WAS!"