We do not know for how long verse 3 lasted. not verse 3 but verse 2.
You were the first I had ever heard say that so it did throw me off a bit. I’m happy to hear that you meant 2. We have enough to discuss without questioning the length of each day of creation.
You asked:
"Why do you need billions of years anyway?
Why is it so important to not believe in a six day creation of all things?"
Where did I say I needed a billion years?
You did not explicitly say it.
People who believe in the gap usually take up the dating assumptions that “science” does.
What difference does it make whether you believe in billions or millions if you believe in an incubation period before a six day creation.
IMO a one week gap is too large a gap to fit biblical narrative.
Have I said I do not believe in a six day creation?
I don’t find six day creation to be compatible with a gap.
So if you defend a gap, I believe you make exceptions that ought not to be made in order to say you believe in a six day creation.
As I have said my trust in God is based on the totality of scripture starting with Gen 1:1 In the beginning God created... That answers the question of why there is something, instead of nothing.
Exodus 20:11
For in six days the LORD made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the LORD blessed the sabbath day, and hallowed it.
Before the first day there was not heaven, earth sea or anything in them.
Heaven, earth, and sea are as the canvas that an artist begins to create on. So in the beginning (of the week), God put up the canvas, created the heavens and earth and seas. On day one He made darkness. On day one He made light. God made light and darkness incompatible on day one.
The first thing God did on the first day was create time-“in the beginning,” space-“heaven,” and matter- “the earth.”
Gen 1:2 וְהָאָ֗רֶץ H776 And the earth הָיְתָ֥ה H1961 was תֹ֙הוּ֙ H8414 without form וָבֹ֔הוּ H922 and void וְחֹ֖שֶׁךְ H2822 and darkness עַל־ H5921 upon פְּנֵ֣י H6440 [was] upon the face תְה֑וֹם H8415 of the deep וְר֣וּחַ H7307 And the Spirit אֱלֹהִ֔ים H430 of God מְרַחֶ֖פֶת H7363 moved עַל־ H5921 over פְּנֵ֥י H6440 the face הַמָּֽיִם׃ H4325 of the waters Hebrew Study Bible
H8414
A masculine noun meaning formlessness, confusion. The exact meaning of this term is difficult at best since its study is limited to its relatively few [20] Old Testament occurrences. It is used to describe primeval earth before the seven creative days (Gen_1:2);...It represents chaos, confusion, and disorder, all things that are opposed to the organization, direction, and order that God has demonstrated.
It also means that dinosaurs, previous civilizations like “Satans earth dominion,” Lilith and all the other strange ideas couldn’t have been there because they not only represent form but they have form so they don’t fit within the context of verse 2.
H922
A masculine noun indicating void or emptiness. It depicts the state of matter after God had created it but before He had fashioned it for habitation (Gen_1:2). WordStudy Dictionary
This doesn’t indicate any amount of time elapsed. It only says that at 00:00:00 (the beginning) God created the heaven and the earth.
Gap is a superimposed idea that doesn’t match with Exodus 20, and other creation narratives from Scripture.