Korihor is described in Alma 30 as professing:
1) That Christ would not come in the future, and that to hope for his coming was foolish.So far, most of these statements certainly sound like some of the things we might hear coming from folks like Richard Dawkins and Sam Harris. However, the text continues, explaining that in addition to these beliefs, Korihor professed that:
2) That no one can know of things to come, or of things that one cannot see.
3) That belief in Christ is the result of a delusion (a "frenzied mind").
4) That belief in Christ is exploited by religious leaders to deny people their freedom, and to live a life of ease while they sap their followers of their income.
5) That there is no God, and that one should only believe in God if one has tangible signs of God's existence.
6) "Every man prospered according to his genius, and that every man conquered according to his strength; and whatsoever a man did was no crime." (v. 17)
What's worse though, is that at the end of the story Korihor confesses:
1) That he was lying all along, and that he actually always knew there was a God, and (the next one's the zinger),
2) That he taught what he taught because he was commanded by an angel to do so.
The classic Biblical proof text against atheism is, "The fool hath said in his heart, There is no God" (Psalm 14: 1 and 53: 1). Korihor may have been a fool, but he was not that kind of a fool. The text states explicitly that Korihor knew in his heart that there was a God, but had entered into a perverse pact with the devil to dissuade people from faith and lead them to commit all sorts of crimes in spite of this knowledge.
The scriptural concern with the denial of God -- both in the story of Korihor and in Psalms and elsewhere -- is focused on the relationship between belief and behavior. The preeminent concern in scripture in relation to the denial of God has to do with whether such a denial is used to rationalize bad behavior, behavior that usually manifests in the form of pursuit of selfish interests without concern for the effect that such pursuit has on others. In other words, in the form of pride and disregard for the poor and vulnerable. The scriptures condemn rationales which suggest that there will be no final reckoning, no final judgment, therefore we may do as we please no matter whom we harm. In other words, the scriptures condemn egotistical nihilism, not necessarily atheism per se.
Thus, for instance, in Alma 30, the author is quick to stress:
Now there was no law against a man’s belief; for it was strictly contrary to the commands of God that there should be a law which should bring men on to unequal grounds. For thus saith the scripture: Choose ye this day, whom ye will serve. Now if a man desired to serve God, it was his privilege; or rather, if he believed in God it was his privilege to serve him; but if he did not believe in him there was no law to punish him. But if he murdered he was punished unto death; and if he robbed he was also punished; and if he stole he was also punished; and if he committed adultery he was also punished; yea, for all this wickedness they were punished. For there was a law that men should be judged according to their crimes. Nevertheless, there was no law against a man’s belief; therefore, a man was punished only for the crimes which he had done; therefore all men were on equal grounds. (vs. 7-11)
It is worth stressing that this text supposedly condemning atheism stresses that it is "strictly contrary to the commands of God" to discriminate under the law between those who believe and those who do not believe in God. Furthermore, it treats lack of belief in God in rather value-neutral terms. "If a man desired to serve God, it was his privilege; or rather, if he believed in God it was his privilege to serve him." There's no statement here as to whether the failure to believe was culpable; only that if one did believe, one might be privileged to act in accordance with that belief, and that if one did not believe, one should not be punished.
While Korihor set out with an agenda to destroy both faith and social order, the agenda of rationalist materialism is to understand the nature of the world we live in through observation of physical phenomena. For modern rationalist materialists there is no explicit agenda of denying God or the social order, but rather simply to understand the physical world. As a philosophy, rationalist materialism is concerned with the existence of God only to the extent that God is observable within the material world. To the extent that God is not observable within the material realm, rationalist materialism is indifferent to God; neither invested in denying nor in proving God's existence.
Where concern about belief in God becomes a factor to rationalist materialists is when claims about God are used to promote or justify repression of dissent, social inequality or violence. Modern rationalist materialists and secular humanists are extremely concerned about creating and preserving a just social order in which, as Alma 30: 7 puts it, none are on "unequal grounds" as a result of their belief or lack thereof. They are extremely concerned about religious violence and bigotry.
Secular humanists and rationalist materialists typically condemn belief in a God who who has at various times commanded slavery, genocide, crusades against unbelievers, and the oppression of women; who is indifferent to poverty and human suffering; who is believed in blindly and unquestioningly; and who commands the use of physical compulsion and violence against those who refuse to believe in such a God. From a scriptural perspective, that God is "the God of this world," Satan wearing a god-like mask, resorting to pious postures while extracting worldly obedience through force. So from a scriptural perspective, the denunciation of such a God would actually be less the work of a Korihor, and more the work of modern day prophets.
Do I see in my atheist friends a desire to undermine faith? A desire to dissuade believers from acting in a socially responsible, law-abiding manner? Not only do I not see this, but I see this kind of concern about how to relate to believers in a way that is respectful, along with a willingness to wrestle with the implications of one's one lack of belief in light of others' belief.
I am a believer. In fact I would say that in light of my own experience with God, it would be easier for me to disbelieve that I exist in some objective sense than it would be for me to deny God. I have experienced God literally as the ground of my existence. But I think that atheism -- at least as it is expressed in the form of rationalist materialist or secular humanist philosophies -- should not worry believers. To condemn that kind of atheism, as far as I am concerned, is a big, fat red herring, designed to make us lose perspective, to forget what true belief really should be all about.