Alvin Plantinga has developed a model where basic Christian belief can be rational and warranted. I will outline it here. For a better and more in depth treatment see "Warranted Christian Belief". According to the model humans have fallen into sin and this has disrupted or clouded our awareness of God. It affects not only our rational faculties but our affections as well. They have malfunctioned or are to some degree dysfunctional (some worse than others). When these faculties are functioning properly (the way they ought) we will come to sense God's presence. Not only from looking at a beautiful sunset but the beautiful Christ in the Gospel as well. When things go as they ought to (according to a design plan) we will love God above all else and our neighbor as our self. The Holy Spirit produces within that firm and certain knowledge (faith) that we are loved by Christ. When held firmly enough these beliefs will constitute knowledge. Because the beliefs and affections are functioning properly according to a design plan successfully aimed at the production of true belief we are justified and rational in holding our beliefs. Plantinga doesn't claim to argue or prove that God exists or that Christianity is true. These beliefs just rise up within. But FOR THOSE who have changed and love God above all else and their neighbor as their self their beliefs and faith in Christ have warrant FOR THEM and they are rational in holding them. That is, they are functioning properly according to a design plan. God's design plan. And are therefore rational.
Evil eros seeks only the pleasures of money, fame and sex. Holy eros seeks the joy of giving and union with Divine Beauty. It yearns for the final reward of heaven.