Well since i am the one on this thread that mentioned and holds to the "gap theory" i will respond.
I agree that no one here can 100% prove there theory, it is just us trying to figure out a bit of God's story. Thats cool, i am all about seeking out truth, and while knowing the details of how God created everything isn't necessary for me to serve him or have a relationship, it is interesting.
I am surprised more people don't give this theory a chance. It allows for all the scientific research and a literal translation of creation in Genesis. (Gotta say i would go for the bible over science, but i don't think thats the way God set it up. God put all scientific laws into motion, and holds them there. We just sometimes don't understand how science lines up with the bible, or how to interpret the bible).
First off, we know for a fact that there is a "gap" in-between Gen. 1:1 and 1:2. It is in the grammar of Hebrew, i am not a professor of it myself but we do have a hebrew professor at my church with 30+ years exp. Now this grammar whatchamacallit (hehe) is there, i don't think any hebrew person will disagree with that. its just how long this gap is. you can not tell, it is just a break it could be a second or it could be a billion years. it is not specific as to how long the break is.
We do know some of the events that would have had to go on in this time, like the creation of the angels and the eventual rebellion, and fall of satan. (you can read up on this on the "antichrist" thread i believe or read bits about this in Jeremiah and Isaiah.) How long would it take for Satan to begin to harbor this lust for power in his heart and raise up a rebellion? i don't know?
Still if you go to this theory as i, the earth was created and could have had all sorts of creatures on it and they could have evolved and had dinos and every bit of the stuff from your science class. then with satans fall, God casts him down to earth. Satan and his trash the place pretty good and ruin the earth, and all life on it. The holy spirit moves across the earth and it is formless and void. then back into Genesis. I guess people just don't want to think they were second to be created but we know from other parts in the bible that the heavens and angels were created before us.
I like this theory best, because we don't doubt the word of God at all, we just realize there is more to God's character and plan than is contained in the bible. the bible is just the instructions/plan for us christians on earth.
Science, why get mad at that? they are just trying to understand God's creation from the facts. We just need to also remember that God made the laws and he bend them or break them.
We are saved by grace thru faith, not of works... "keep on fighting for grace"