Well the best answer is " Deception", they have been deceived. In Rev. 12:9, the devil has deceived the whole world, and Christians are not excluded from that. The seduction of the Christian mind has been a dazzeling display of satans power to seduce. And the devil has used the bible to do this; its easier to seduce a believer, if you use the bible and a church, or a pastor or a preacher. You make the believer think that what they are believing is God's will. In this manner satan " Appears as god" to them, and the seduction is made complete.
satan, years ago, even changed how the bible was being translated, because hell does not even appear in the original text. Its been a masterful seduction of the believing mind; its VERY well planted now, and cannot be uprooted by any power but God; so God is aware of this. Its not the believers fault, because powers FAR greater than they have completed the deception before they were even born. They were raised with hell, taught it from their birth. More than one religion is teaching it, more than one culture believes it; its really been a worldwide deception.
Anyone who believes it, is just deceived; blind; totally off base concerning what God will do with unbelievers. Some believers here will fight for hell; they will argue for it to be true! They will call you a blasphemer if you don't believe it. Its a stunning deception, and absolute proof to me that the powers of deception are absolute and incredible in their reach and ability. Some believers are more excited about hell than they are heaven. The power of deception is gripping; for example;
Not long ago a rumor started in the church, through pastors and teachers, that the bible mentions hell more than it does heaven. A stunning lie, but as usual , it caught fire and millions of believers swallowed it, hook, line and sinker; the sheer power of deception. Hell is mentioned 54 times in some bibles, heaven is mentioned over 1500 times in all bibles. Its not even close. And a simple study and short research of any concordance would show anyone this, but people just will not study.
A real study of the history of hell would show people the truth, but they cannot see it because of the spirit of stupor that comes with hell belief, is over them. Its a spirit that wants to keep the person in ignorance, and most of the people " Love the deception." They don't WANT to let it go. In example, a simple true study of Christmas and Easter would reveal the obvious pagan origins of them, but people love these holidays and don't want to give them up. They are their traditions.