What It Means to be a Christian

is a great book. The heart of the Christian response to Jesus's gift:

Becoming a Christian is not at all something given to us so that we, each individual for himself, can pocket it and keep our distance from those others who are going off empty-handed.  No: in a certain sense, one does not become a Christian for oneself at all; rather, one does so for the sake of the whole, for others, for everyone.  The movement of becoming a Christian, which begins at baptism and which we have to pursue through the rest of our lives, means being ready to engage in a particular service that God requires from us in history.  We cannot of course always think through in detail why this service has to be done by me, now, in this way.  That would contradict the mystery of history, which is woven together from the inscrutability of man's freedom and God's freedom.  It should be enough for us to know in faith that we, by becoming Christians, are making ourselves available for a service in the whole.  Thus, becoming a Christian does not mean grabbing something for oneself alone; on the contrary, it means moving out of that selfishness which only knows about itself and only refers to itself and passing into the new form of existence of someone who lives for others.--Joseph Cardinal Ratzinger (Pope Benedict XVI), What It Means to Be a Christian, (San Francisco: Ignatius Press, 2006), pg. 54-55