Christian conservatives, i.e. especially evangelical and fundamentalist Christians, typically believe that those who, for whatever reason, do not "accept Christ" as savior in this lifetime, are condemned to hell for all eternity. They believe that because the Bible says so, and they accept it as being God's privilege and prerogative to condemn people to hell. They do not, and typically dare not, question what is said in what is considered to be the "Word of God", aka the Bible.
Some psychological factors would work to make those who believe that some people are going to hell to also accept torture.
Psychologically it is really no different to go along with political authorities who say that torture is acceptable, or for that matter to go along with Hitler's regime in Germany, than it is to unquestioningly accept that some people are going to be condemned to hell for all eternity because the Bible, the so-called and so-considered "Word of God", says so.
Also I think there is a psychological tendency to become like that which one worships.
Bob Altemeyer, associate professor of psychology at the University of Manitoba, has an
http://home.cc.umanitoba.ca/~altemey/">online book about authoritarians and the authoritarian personality, which includes a
http://members.shaw.ca/jeanaltemeyer/drbob/chapter4.pdf">chapter on Authoritarian Followers and Religious Fundamentalism.
The Swiss writer and psychotherapist
http://www.alice-miller.com/index_en.php">Alice
http://www.naturalchild.com/alice_miller/">Miller, especially in her book
http://www.nospank.net/fyog.htm">For Your Own Good (a phrase my father used very often), describes the process by which people come to unquestioningly accept what they are told they are supposed to accept by whatever authorities, namely the person's upbringing. Here is a
http://www.nospank.net/fyog10.htm#central">telling quote from her book For Your Own Good:
This perfect adaptation to society's norms--in other words, to what is called "healthy normality"--carries with it the danger that such a person can be used for practically any purpose. It is not a loss of autonomy that occurs here, because this autonomy never existed, but a switching of values, which in themselves are of no importance anyway for the person in question as long as his whole value system is dominated by the principle of obedience. He has never gone beyond the stage of idealizing his parents with their demands for unquestioning obedience; this idealization can easily be transferred to a Führer or to an ideaology. Since authoritarian parents are always right, there is no need for their children to rack their brains in each case to determine whether what is demanded of them is right or not. And how is this to be judged? Where are the standards supposed to come from if someone has always been told what was right and what was wrong and if he never had an opportunity to become familiar with his own feelings and if, beyond that, attempts at criticism were unacceptable to the parents and thus were too threatening for the child? If an adult has not developed a mind of his own, then he will find himself at the mercy of the authorities for better or worse, just as an infant finds itself at the mercy of its parents. Saying no to those more powerful will always seem too threatening to him.
Finally, it was
http://thinkexist.com/quotation/as_long_as_people_believe_in_absurdities_they/186698.html">Voltaire who said, “As long as people believe in absurdities they will continue to commit atrocities”. Or accept atrocities, or advocate in favor of them.