Stupendous words of the ancient Letter to Diognetus, which describes the absolutely essential mission of Christians in the world. (Lifted from Christianity and the Crisis of Cultures by Pope Benedict XVI, then Joseph Cardinal Ratzinger)
For Christians are not distinct from other men in terms either of their territories, their language, or their way of life… They live in the cities of the Greeks or the barbarians, as the lot has fallen to each one, and they adapt to the customs of the place in their clothing and food and in the rest of their way of living, offering the example of their marvelous form of social life, which all admit has something incredible about it. They live each in his own native land, but as if they were foreigners. They take their share in all the burdens, as citizens, and they put up with everything, as strangers. Every foreign land is a native land for them, and every native land is a foreign land. They get married like everyone else and have children, but they do not expose their newborn children. They share their table, but not their beds. They live in the flesh, but not according to the flesh. They dwell on earth, but they are citizens of heaven. They obey the laws that have been laid down, but with their manner of life they rise above the laws. They love all and are persecuted by all… To put it in a word, Christians are in the world what the soul is in the body… The soul loves the flesh that hates it and loves its limbs: Christians, too, love those who hate them. The soul is shut up within the body, but it is the soul that sustains the body: Christians, too, are held in the world as in a prison, but it is they who sustain the world… God has assigned them such a high position, and they are not allowed to abandon it.