The knowledge of what It means to be a person is inextricably bound up with the faith of Christianity. An affirmation and a cultivation of the personal can endure for a time perhaps after faith has been extinguished, but gradually they too will be lost.
As unbelievers deny the revelation more decisively; as they put their denial into more consistent practice, it will become the more evident what it really means to be a Christian. At the same time the unbeliever will cease to reap benefit from the values and forces developed by the very revelation he denies. Nietzsche has already warned us that the non-Christian of the modern world has no realization what it truly means to be without Christ. The last decades have suggested what life without Christ really is. The last decades were only the beginning.
– Romano Guardini , c.1949