Modern theology can show that a reasonable and self-determined approach to fertility fits fundamental Christian ethical values much better than more or less uncontrolled fertility. In the “kingdom of God” which was expected by Jesus and the early Christians as imminent to arrive, there would be no more marriages or families. There is no such thing as a “Christian family-concept” in the New Testament; the “Christian family” is the family of God: the church. As every individual is self-responsible for his or her belief, he or she is also self-responsible on the field of sexual behavior: loving respect for the other is the only law. There is also no evidence that the Bible sweepingly condemns technical instruments of birth control. This claim is supported in this chapter. Nevertheless, even for a very advanced, academic theology like that in Germany in twentieth century, it took a long time to reach this insight. Even there, conservative and paternalistic sexual ethics with their restrictive view of contraception were dominant for decades. The retreat battle to defend such supposed “Christian family values” was fought against extramarital sexual intercourse. Even this battle was finally lost. Love and responsible sexuality cannot be restricted to the institution of marriage. To deal responsibly with fertility, to find the right way of contraception, is the right and the duty of all couples—be they married or unmarried.