In first century Judea, betrothal was a very different concept than that of twentieth century ideas of an engagement; the period of betrothal occurred after the main marriage ceremony had taken place and the marriage contracts had been signed, and was very much a till death do we part affair, at least until a formal divorce was granted. Normaly the betrothal ceremony took place when the woman was still very young, generally around age twelve or thirteen, and after the ceremony she would remain in their father’s house for around a year. At this point the husband would bring the bride into his own home – which most scholars think is the meaning of Mary being pregnant before they came together; Mary being pregnant before the two shared a home, rather than stating that she became pregnant before the two had had sex, although it could be interpreted this way.
Matthew merely glosses over how Mary came to be pregnant, which Schweizer thinks implies that Matthew’s audience were well aware of the story of the Virgin Birth – there were several virgin birth stories in the Jewish tradition and so the idea of virgin births was generally accepted by the population – though it could just as easily be explained by Matthew trying to avoid discussing any implication of pre-marital sex. Matthew mentions the paternity of the Holy Ghost very quickly, even before any of the characters in his narrative are aware of this fact, which Brown argues is because Matthew does not want the reader to ever consider alternate scenarios as to how Mary could have become pregnant. It is worth noting that in Greek, the term Holy Ghost is gender neutral and in Semitic languages it is female, thus Matthew, so Matthew’s audience may have been likely to take this to dispel notions of actual copulation, like the myths surrounding several ancient gods and mortal women, although the grammatical gender of abstract concepts frequently has no relation to their natural gender, and so the wording could still describe an actual sexual act.
Matthew 1:25 is, however, quite explicit that Joseph could not be the father of Jesus, stating that Mary and Joseph had not had sex before Jesus was born. This is frequently extrapolated by supporters of the concept of a Virgin Birth to imply that not only had Mary not had sex with Joseph before Jesus was born, but that she had also had sex with no-one else, i.e. was a virgin. Older and more puritanical translations often bowdlerized this passage using more euphemistic wording, though modern versions are much more explicit about the lack of sex. Many Protestants take the verse to imply that Mary and Joseph had sex after Jesus was born, but other groups, particularly the Roman Catholics, argue that the passage is far vaguer in the original Greek than it is in English, and support the idea that Mary permanently remained a virgin. David Hill, a Presbyterian, acknowledges that the wording does not absolutely deny perpetual virginity, but argues that if the idea had been current at the time, then Matthew would have been more explicit about it. Curiously, the Genealogy of Jesus in the oldest surviving copy of the Gospel of Matthew – the Codex Sinaiticus – appears to explicitly state that Joseph was the father of Jesus..