Someone who hates atheists on the basis of their lack of belief in God is evincing an un-Christian attitude. They ought to confess, be penitent, and seek forgiveness from God and man to lessen the peril to their soul.
Well, Dimensio - Christians are taught to love everyone, including their enemies (and including atheists). But you can love someone and disagree vehemently with him at the same time, yes?