1 Peter 2:11-12 Beloved, I urge you as sojourners and exiles to abstain from the passions of the flesh, which wage war against your soul. 12 Keep your conduct among the Gentiles honorable, so that when they speak against you as evildoers, they may see your good deeds and glorify God on the day of visitation.
The following text is from the Epistle to Diognetus. This epistle is an anonymous apology (reasoned defense or presentation) for Christianity of uncertain date but usually placed in the second century.
“For Christians are distinguished from other people neither by country, language, nor customs. They do not dwell in cities of their own, nor do they use some strange language, nor practice a peculiar kind of life. Their teaching indeed has not been discovered by any speculation or consideration of persons full of curiosity, nor do they busy themselves with human doctrine as some do. While dwelling in Greek or barbarian cities, as each has received his lot, and following the local customs in dress, food, and the rest of life, they display the marvelous and admittedly unusual constitution of their own citizenship. They live in their native countries, but as sojourners. They share all things, as citizens; and they endure all things, as foreigners. Every foreign land is their fatherland, and every fatherland is a foreign land to them. They marry as do all others; they bear children; but they do not abandon their offspring. They furnish a common table, but not a common bed. Their lot is cast “in the flesh,” but they do not live “according to the flesh.” They pass their time upon the earth, but their citizenship is in heaven. They are obedient to the appointed laws, but they surpass the laws in their own lives. They love all people and are persecuted by all. They are not understood, and they are condemned. They are put to death, and they are made alive. “They are poor, and they make many rich.” They lack all things, and they abound in everything. They are dishonored, and they are glorified in their dishonor. They are evil spoken of, and they are justified. “They are reviled, and they bless.” They are insulted, and they give honor. While doing good, they are punished as evil. Being punished, they rejoice as being made alive. They are fought against as foreigners by the Jews, and they are persecuted by Greeks. And those who hate them cannot state a reason for their enmity . . . And Christians live in the world but are not of the world” (XVI.4).
Everett Ferguson wrote concerning the above quotation: The author’s picture of the Christian life is one of the most beautiful literary gems from early Christianity . . . his ethics are superb (Early Christians Speak, Vol. 1 3rd ed.).