"Sex and marriage occupied far more prominent places in St. Paul's writings than they did in the gospels, and Paul became far and away the most influential authority in shaping early Christian treatments of these issues. Paul treated sexual behavior as one of the major sources of sin. Indeed, he thought that illicit sex was as serious a moral offense as murder. In his writings about sex, Paul developed an implicit theory of sexual sin that distinguished four types of offenders: prostitutes, adulterers, what he called "the softies" (1 Corinthians 6:10), that is people who used sex primarily as a source of pleasure, and men (but perhaps not women, since he did not mention them) who had sex with one another. Marriage in Paul's view, was good, but considerably less good than virginity, for a Christian. He taught that marital sex joined husband and wife together both physically and spiritually. It made them two in one flesh, just as a Christian's spiritual union with Jesus joined two persons in a single spirit. Precisely because martial sex was tinged with the sacred, any type of extramarital sex in Paul's view was worthy of damnation."