Actually, the "giants in the land in those days" has been the subject of vigorous whitewashing out of Holy texts by well-meaning religious authorities of Judeo/Christianity (often such teaching is considered heresy and some rabbis of great authority have even pronounced a curse on those who teach it). And the concept of giants and fallen angels is not limited to Judeo/Christianity but, like stories of a Great Flood, are common in nearly ALL ancient religions, texts, mythologies.
I don't think any religion pushes the idea that acceptance or denial of "giants" plays a role in whether one goes to heaven or hell (and I doubt snake handlers have any knowledge of the sources of information on said giants--the Pseudepigraphical Book of Enoch comes to mind), but you do raise a very interesting issue with your mention of "there were giants in those days."
Funny thing that the Book of Enoch has been actively hidden by many, many religious authorities, but keeps popping up. Most recently, it popped up in the fragments of the Dead Sea Scrolls found at Qumran in 1946-1954...most inconvenient!
As a final point, let me add the these "giants" in question were said in ancients texts to be the offspring of fallen angels and the daughters of humans. They were powerful in a thousand ways and vile in even more. These giants (one of the many names for them was "nephilim") introduced such evil to humanity that God ultimately concluded that their DNA had to be expunged from the earth. His solution was the Great Flood.
These giant in question are the same as those mentioned in all ancient literature, from Greek mythology all the way back to the Epic of Gilgamesh.
We also had FOUR species of rattlesnakes available, and plenty of copperheads, and sometimes even water moccasins. I gather a good availability of poisonous snakes attracts that bunch.
Now, regarding giants, when the Europeans first encountered the Iroquois and Mohican warrior elites they realized things were going to be difficult. Seems that in raising up those elites for a life as warriors the tribes adopted in every large boy for hundreds of miles around ~ like our basketball teams do ~ and these guys were large, muscular and about 7 feet tall!
To your typical 5'1" Late Medieval white fella' they must have seemed like giants.
The Sa'ami from Mt. Keppel in Norway, most of whom were dwarves, must have imagined the exceptionally tall Viking warriors who were gobbling up the South shore of the Baltic to also be giants. Yet, a typical raid would have both Sa'ami dwarves and Viking giants ~ and a whole big bunch of rather average size guys as well.