Does this dismiss Christianity as impratical/invalid?

[Lion eats man]

This is the fundamental belief among most if not all Christian denominations. Of course there are some minor specifications that vary but in general it goes something like this:

People who don't accept Jesus Christ as atonement for their
sin go to hell.

For those who don't know.

I'm having trouble determining what words express my question clearly but here it is:

Does the possibility(because I'm not entirely sure if it is really a logical fallacy) that it is a logical fallacy, render it invalid? If so does it render other beliefs founded upon it invalid?