But refuse to enroll younger widows, for when their passions draw them away from Christ, they desire to marry and so incur condemnation for having abandoned their former faith. . . . So I would have younger widows marry, bear children, manage their households, and give the adversary no occasion for slander. For some have already strayed after Satan. (1 Tim 5:11-15)
Even the apostles considered vows of a monastic kind to be extremely serious. There were many widows who were fully supported by the Church, and they typically made vows to serve the Church by serving the poor and dedicating their lives to prayer and good works. Dorcas (Acts 9) was one example. Hence the necessity to regulate who qualified for such work.
In the passage cited above we can see St. Paul, who considered marriage as the creation of God, giving instructions to Timothy and directing that he wants young widows to marry; and at the same time stating that widows who had made monastic vows of celibacy and devoting their lives to prayer (and thus being fully supported by the Church), and who later break that vow in order to marry, are actually following Satan. These are very strong words.
So for St Paul, to abandon the vow of celibacy and prayer, in order to get married, is in a sense, a self-condemnation, a sentence of death. Conversely, not to make the vow of celibacy and prayer, in order to marry and raise a family, is to attain life in the sacred calling of marriage.
(Of course, St Paul had much more to say about marriage elsewhere, but what is interesting in this passage is what he notes about the vows of celibacy made by the widows.)
This also reminded me of the story about the elder in Mount Athos giving advice to a catechumen who was just about to be baptized. Upon hearing about his upcoming baptism, the elder was elated, and when the young man asked him for advice, the geronta answered, “you must either marry or become a monk.” As the catechumen seemed a little puzzled, the elder repeated it again for emphasis: “you must either marry or become a monk.” Those are the only two callings in the Christian life.
The explanation was that “we Christians are not meant to live alone. We are called to be part of a family. We thus have a choice: either make a new family or join an existing one.”
Both involve a vow that cannot be broken.
 Graham Speake, Mount Athos – Renewal in Paradise, p. 260.