From Benedictus: Day By Day with Pope Benedict XVI, the entry for March 7:
Moral obligation is not man’s prison, from which he must liberate himself in order finally to be able to do what he wants. It is moral obligation that constitutes his dignity, and he does not become more free if he discards i: on the contrary, he takes a step backward to the level of a machine, of a mere thing.
If there is no longer any obligation to which he can and must respond in freedom, then there is not longer any realm of freedom at all. The recognition of morality is the real substance of human dignity: but one cannot recognize this without simultaneously experiencing it as an obligation of freedom.
Morality is not man’s prison but rather the divine element in him… For nature is not — as is asserted by a totalitarian scientism — some assemblage built up by chance and its rules of play but is rather a creation. A creation in which the Creator Spiritus expresses himself.
This is why there are not only natural laws in the sense of physical functions: the specific natural law itself is a moral law. Creation itself teaches us how we can be human in the right way.
The Christian faith, which helps us to recognize creation as creation, does not paralyze reason; it gives practical reason the life-sphere in which it can unfold. The morality that the Church teaches is not some special burden for Christians: it is the defense of man against the attempt to abolish him. If morality — as we have seen — is not the enslavement of man but his liberation, then the Christian faith is the advance post of human freedom.