You are assuming there is a gap in Genesis 1:1 and Genesis 1:2...he apparently did not make such an assumption..
Perhaps "gap" was the wrong word. But Genesis 1:1 covers a period of indeterminate length before the famous creative week. There's little reason to assume Gen 1:2 and the creative week (literal or otherwise) happened immediately after the creation of the universe ex nihilo.
"You are assuming there is a gap in Genesis 1:1 and Genesis 1:2"
If you assume God would make the earth "without form, and void". I don't believe God screws up when He makes or creates anything. Then you have the problem with Lucifer having a war with God and then him being cast down out of heaven to the earth. Too many problems with no gap.