I need this sort of information to talk about creationism with an agnostic friend of mine. I know about the passages in Genesis, naturally, but I heard there are some more in the book of Job, somewhere. Also, I believe there are some other passages about creation I certainly haven't heard about.
The main text on the subject of creation is the Genesis account. The first few chapters are there to present how God created the world, not to present a twenty-first century scientific thesis. So God provided a simple explanation. A bit like saying that the sun rises instead of talking of the rotation of the earth around the sun.
This being said, this part of the Bible is regarded in many different lights. The first position is the literal position, which says that the heaven and earth were created by God in 6 twenty-four hour periods. This position is held by Answers in Genesis for example.
Another position is that the first few chapters of the Bible are poetry. Then you can believe anything you want on the subject of creation, because the author of Genesis uses poetry as he opens his book.
Then there are positions between the two poles described above:
The rest of the Bible and creation
The six days of creation are quoted elsewhere in the Bible:
Exodus 20:11 (ESV) For in six days the LORD made heaven and earth, the sea, and all that is in them, and rested on the seventh day. Therefore the LORD blessed the Sabbath day and made it holy.
Exodus 31:17 (ESV) It is a sign forever between me and the people of Israel that in six days the LORD made heaven and earth, and on the seventh day he rested and was refreshed.
The Bible present Jesus has the author of creation in a few verses. (This make biblical sense because Jesus is the word of God, and in creation the only tool used is the word of God.)
John 1:1-4 (ESV) In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through him, and without him was not any thing made that was made. In him was life, and the life was the light of men.
Colossians 1:16 (ESV) For by him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities—all things were created through him and for him.
The passage in Job you mentioned is
Job 40:15-18 (ESV) “Behold, Behemoth [The ESV study Bible comment on the Behemoth is 'A large animal, exact identity unknown'], which I made as I made you; he eats grass like an ox. Behold, his strength in his loins, and his power in the muscles of his belly. He makes his tail stiff like a cedar; the sinews of his thighs are knit together. His bones are tubes of bronze, his limbs like bars of iron.
Conclusion From my reading of scripture the Bible supports a literal six-day creation. When did that happen? There are different theories about this as well.
Some argue against a six-day creation, requesting proof. There is no way to prove creationism, but the same is true for evolution. Your position is a question of faith. This being said, it does not mean that you don't ask questions about your position. The starting point of reference in your thinking system, today's science or the Bible, will greatly influence your position.
This might not help you with your discussion with your agnostic friend, but I hope that it helps you in your personal thinking on the subject. Your question is a valid one, but answering it in a few sentences is hard.
No, frankly, there isn't.
Not because it it "wrong" as such, but for the reason that everything in genesis is not testable, cannot be studied, etc. All that is presented is a proposal. Here is an alternative proposal I used the other day (paraphrased):
The world was created by a giant magic spider crab, who likes the colour green; which is why He made a lot of trees green.
The details in the proposal (trees/green) may be consistent with observation, but that is not evidence that the proposal is true. It only says that the argument is not internally inconsistent and/or trivially untrue. This is not evidence in any way, otherwise anything can be shown to be "true". This applies directly to genesis: it is not sufficient to say "see, nothing in there is trivially untrue" (especially when we have to deny existing observation to make even that modest claim).
Since the obvious contrast here (see David's answer) is the scientific approach, and things like evolution; this is testable, and through testing has both proven that it is a useful representation, and provided new approaches (a lot of medical science, for example) that were discovered because of the theory, and their effectiveness directly supports that the theory is valid. The effects of evolution, despite contrary myth, have also been directly observed (not just theorised from fossils). Yes the theory is still evolving [sic], but it is essentially proven.
Religion requires certainty, but the certainty we read into the Bible has differed over the ages. The early Christians had that certainty, as they could not imagine the world existing without a creator to bring it into existence, and so did not need the the creation account to be read literally. Indeed, the early Christian Church Fathers, familiar as they were with the Bible, did largely read the Genesis creation history as an allegory.
Augustine emphasised that the text was difficult to understand and should be reinterpreted as new knowledge becomes available. In the Middle Ages, Thomas Aquinas asserted one should not adhere to a particular explanation, only in such measure as to be ready to abandon it if it be proved with certainty to be false, lest holy Scripture be exposed to the ridicule of unbelievers. We can see in these two examples a focus of interpretation on what is useful rather than a strict and therefore unchanging meaning.
The Book of Exodus (20:11, 31:17) says that God really did create the world in six days, just as a literal reading of Genesis chapter 1 would tell us, removing the flexibility that Augustine and Thomas suggested. More than the Book of Genesis, which Augustine described as so difficult to understand, these passages would seem to provide biblical proof of creationism.
Modern scientific knowledge has made it more necessary than in the past that the Bible provide proof of creation, but at the same time more difficult to do so. On the one hand, science has removed some of that certainty that God created the world, as advances such as the Theory of Evolution no longer require a creator God. On the other hand, the biblical creation story is so inconsistent with scientific knowledge that it is hard to support in a fully literal, creationist sense.
The Book of Job contains allusions to God's creation, but those allusions are similar to ancient Near Eastern creation stories that have long since been dismissed as fiction. In Job 40:25-28 God tells Job that he was able to defeat Leviathan, the great chaos monster of which Psalm 74:14 tells us, "You crushed the heads of Leviathan" and which a seal from Tel Asmar (in modern Iraq) depicts as a seven-headed dragon being defeated by yet another god. This can not be regarded as support for creationism in the normally accepted sense. If our definition of creationism is based on a literal six-day creation, then we must rely on Genesis chapter 1 and Exodus.