I would say that they're not really doing the will of the Father in heaven if they're condemning each other to hell. Didn't Jesus sit down with sinners and teach them how to do right? Didn't He say to love your brother and your enemy? To turn the other cheek? To forgive someone always? Not to judge, because if you judge, you will be judged? As you can see, telling someone that they're going to hell is judging that person, which is against the true Christian ideal.