God made the Earth from pre-existing water

God Made the Earth from Pre-existing Water.

Why God didn't create out of nothing. 

God hovered over primeval water, about to form the heavens and the earth.

As Genesis says--

Genesis 1:1 In the beginning God created the heavens and the earth. 2 The earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters. 3 And God said, "Let there be light, and there was light." 

The water existed before God began to make anything. The water wasn't commanded to appear. The first command made light come. One view is that the water was created, where it says--

"In the beginning God created the heavens and the earth." 

But it's still not made plain that the water was created.
Besides, the opening line is often understood to be only a topical sentence, a summary of what's to come.  

Meantime, the New Testament says God formed the earth out of water--

 2 Peter 3 Long ago God gave a command, and the heavens and earth were created. The earth was formed out of water and by water.

 But Genesis says that the land already existed beneath the water--

Genesis 1:9 And God said, Let the water under the sky be gathered to one place, and let dry ground appear. And it was so. 10 God called the dry ground "land," and the gathered waters he called "seas." And God saw that it was good. 

2 Peter and Genesis make different claims.  

Another outside-the-Bible view says that supernatural war destroyed the previous earth.

Apologists say that there was the first-time formation of the heavens and the earth. Then God made angels, the angel Satan warred with God, and the earth was destroyed in the battle. The war, apologists say, had reduced the earth to water. Out of the chaotic water, God reformed the earth during the six days of creation.

The thing is, tradition and not the Bible proposes the primeval war in which the earth was reduced to ruins. 

Okay, but God and Satan are on speaking terms, not at war, in the Old Testament book of Job--

Job 1:6 One day the angels came to present themselves before the Lord, and Satan also came with them. 7 The Lord said to Satan, "Where have you come from?" Satan answered the Lord, "From roaming through the earth and going back and forth in it." 8 Then the Lord said to Satan, "Have you considered my servant Job? There is no one on earth like him; he is blameless and upright, a man who fears God and shuns evil." 

Thus God and Satan engage in dialog in the book of Job. Moreover, Satan roams the earth as he pleases, as if God and Satan had made up after the supposed war between them. Uh ... 

As for the idea of creation from nothing, the book of Maccabees (it's included in some Bible editions) might have started the view of creation from nothing--

2 Maccabees 7:28 I beseech you, my child, to look at heaven and earth and see everything in them, and know that God made them out of nothing; so also he made the race of man in this way. 

But Genesis says God made humans--the race of man--from clay and his breath, not nothing.

2 Maccabees (120 BCE) has misspoken itself about humans.

The question is whether it screwed up about the earth out of nothing, too.  

Some ancient Bible intellectuals favored the concept of creation out of something.

For example, the Christian intellectual Justin Martyr (2nd century CE) says that material pre-existed for God to use. He says that it was the water over which the spirit of God hovered, and then God shaped it (Justin Martyr, 1 Apology 59).  

As another example, Philo of Alexandria, a Jewish theologian (early 1st century CE), says God shaped creation out of pre-existing matter (The Eternity of the World 5).

At other times, Philo says some of creation came from nothing (On Dreams 1.76).

Philo appears to straddle the question. 

On the whole, it's not clear if creation was from nothing or pre-existent water.

Me, I side with the interpretation of pre-existent water.