To bear witness to the faith is the main task of our lives. The Christian has a specific duty in life, which is not merely to carry out a given jjob or profession; it is a duty imposed by the Christian's faith to bear witness to the same faith. In addition, Christians must bear witness to the faith in the state of life in which they find themselves.
In doing so, we will exhibit our own personalities - not our personalities as priests, nuns, workers, professionals, or fathers and heads of families, but rather our personalities as Christians.
Thus, the first essential requirement of the Christian personality is a living awareness of the fact that our salvation - or our liberation, which amounts to the same thing - as already been accomplished by One whose Presence is still living and active in the life of man, namely, Christ Jesus.
(Luigi Giussani, from the Introduction)

[Original title: Moralità: memoria e desiderio]