This is an interesting read http://www.prophecyupdate.com/as_in_the_days_of_noah.htm even if you dont believe in them.
Fixed. I believe in Nehi, but I need to validate that belief by seeing if it's in the grocery store. I believe in Neahkahnie, Oregon. Drove through there just this past summer.
Either the Bible is inerrant, or it isn't. The answer to the question posed by teh OP is that, yes, if you claim typical Christianity, then you are committed to this as absolute truth: Either there were giants, and sons of God coming "in unto" daughters of men, or there were not. Not.
Let me put it another way: The story about giants is a history lesson. And that history lesson has nothing to do with Christianity any more than it has to do with Judaism. It is simply a statement about history. Christianity is based on the life of Jesus, and whether or not giants existed a few thousand years prior to Jesus would have no impact on the Jesus story, hence, Christianity would not be effected either way.
So, again, for those, wondering...YES, this is what Christians believe took place, if they are dogmatic Christians. They DO in fact believe in these things. To NOT believe in these things would mean that the entire 66 books were up for interpretations largely different than those currently instituted. DO dogmatics pick and choose? All the time. But, technically, they are committed to all stuff. To the OP, check out Deuteronomy; that's lots of fun to talk with Christians about, particularly in terms of whether they think that much of the Directives in that chapter are right/moral/just. Just keep in mind, the way that dogmatics have structured the Biblical discours,e it's all or nothing. If its not all, then your picking and choosing...why not pick and choose among all of it? Why not indeed.
Christianity, as separate from Judaism, began with the life, death and RESURRECTION death of Jesus Christ. That is why it is called CHRISTianity. That does not mean Christians are unaffected by the OT, it is part of their history as well.
Genesis 6:4-7 The Nephilim were on the earth in those days--and also afterward--when the sons of God went to the daughters of men and had children by them. They were the heroes of old, men of renown......So the LORD said, "I will wipe mankind....from the face of the earth...." When the Isralites came to Israel they find that the place has been populated by giants. "And there we saw the Nephilim and we seemed to ourselves like grasshoppers, and so we seemed to them." Numbers 13:33. The Israelites were instructed to wipe out every man, woman and child of certain tribes (but didnt always do this). Somehow they were able to survive the flood which i dont understand as God said he would wipe out all living things except for Moses with the flood but somehow they survived. Jesus says "As it was in the days of Noah, so it will be at the coming of the Son of Man. " Matthew 24:37
It's Monday, it's crappy weather outside, and I'm looking at a busy week at work. Thanks for putting a smile on my face.