In Männer Glauben Anders, Markus Hofer sketches the situation in the early church: the married men heading local churches and the wandering celibate missionary.
In Death Comes to the Archbishop, it is clear that the missionary priests must be celibate, because they have to be ready to go anywhere, into dangerous situations, on a moment’s notice. Celibacy can be lonely, especially for a missionary far from his native land and extended family, but it is necessary to spread the kingdom. The model of the celibate missionary won out in the Western Church, although it was not observed with great care. The constant legislation against clerical marriage and clerical concubinage indicates that priests were not following the discipline. For a priest who lived in a village his whole life it was hard to see the missionary purpose of celibacy.
After Ignatius of Loyola’s conversion, he established for his followers an intensely masculine environment in which they had to be ready to go anywhere at anytime to do the work of God. It was an adventurous masculine life, and obviously incommpatible with marriage. Ignatius would upset the local clergy in Spain when he arrived and tried to get the local bishop to enforce the discipline of celibacy.
The missionaries of the Church have an obvious connection with celibacy. While I respect married Protestant missionaries, I wonder how they can bring their wives and especially their children into dangerous environments. These do not have to be in the recesses of Africa or New Guinea. Many urban areas are dangerous, both in the United States and Europe. A priest in Naples who tried to keep young men out of organized crime was murdered by the Mafia.
Perhaps (and I emphasize perhaps) the missionary vitality of the Western Church as compared with the Eastern Churches is at least in part explained by the celibacy of it clergy.
As to celibacy being a sign in a sex-obsessed age – I don’t know. We do not know how often violations, even criminal violations, occur; but they get a lot of publicity and they discredit celibacy, and give evidence for the belief that celibates are hypocrites. However, I have been researching the anticlericalism of the Spanish Civil War, and the anticlericals had a special and intense hatred for truly celibate priests. Some priests were told their lives would be spared if they had sex; the priests refused to violate their vows and were shot – shot if they were lucky. Sexual torture was a favorite weapon of the Republican anticlericals. So perhaps celibacy is a sign of contradiction, and a necessary one.