Faith is an orientation of our existence as a whole. It is a fundamental option that affects every domain of our existence. Nor can it be realized unless all the energies of our existence go into maintaining it. Faith is not a merely intellectual, or merely volitional, or merely emotional activity — it is all of these things together. It is an act of the whole self, of the whole person in his concentrated unity. The Bible describes faith in this sense as an act of the "heart" (Rom 10: 9). Faith is a supremely personal act ... It transcends the self, the limits of the individual. Augustine remarks that nothing is so little ours as our self. Where man as a whole comes into play, he transcends himself; an act of' the whole self is at the same time always an opening to others, hence, an act of being together with others. What is more, we cannot perform this act without touching our deepest ground, the living God who is present in the depths of our existence as its sustaining foundation. Any act that involves the whole man also involves, not just the self, but the we-dimension, indeed, the wholly other "Thou," God, together with the self. But this also means that such an act transcends the reach of what I can do alone. Since man is a created being, the deepest truth about him is never just action but always passion as well; man is not only a giver but also a receiver ... Faith is a perishing of the mere self and precisely thus a Resurrection of the true self. To believe is to become oneself through liberation from the mere self, a liberation that brings us into communion with God mediated by communion with Christ.
from Benedictus Day by Day with Pope Benedict XVI p.124