You believe they will if they do not "repent" -- that's still a horrible thought to hold toward another human being.
If you were making a "preferred" hang out list for your children would it include people you know are not saved (not just atheists but kids from another religion -- one your sure is marching to hell)?
Plus one type of "saving" is not the same as another.
If you are Scriptura Sola then you must believe that if a man just before his death asks to be saved by a Catholic Priest then by your lot he is going to hell -- to burn forever and ever.
*&^ Constitution --- Constitutional Rationality