Question:

How did we get light on the first day when the sun was not created until
the fourth ?

Answer:

I have studied current theories of the early earth and its atmosphere. As
far as I understand it, the early earth most likely had much higher
quantities of sufur dioxide, methane, ammonia and so forth. I believe it
is extremely likely that the sun and the moon remained invisible to the
eye from the surface of the earth until life on the planet had
significantly changed the chemistry of the atmosphere. As a parallel
example, the heavenly objects are not visible from the surface of Venus
today. In other words, the sun, moon and stars were not visible until the
third or fourth “day” of creation. Obviously, I do not believe that these
“days” are literal twenty-four hour periods, but that they represent
periods, eras over which God did his creative work. So, day and night
existed on the first “day,” the oceans and the atmosphere formed on the
second “day,” life appeared on the third “day,” Life changed the
chemistry of the earth, so that the heavenly objects appeared in the sky
on the fourth “day.” As I have said before, the outline of information
in the Genesis creation account is in remarkable agreement with the
current models used by scientists today.

John Oakes