Paul writes the following to the Corinthians:
I want you to be free from anxieties. The unmarried man is anxious about the affairs of the Lord, how to please the Lord; but the married man is anxious about the affairs of the world, how to please his wife, and his interests are divided. And the unmarried woman and the virgin are anxious about the affairs of the Lord, so that they may be holy in body and spirit; but the married woman is anxious about the affairs of the world, how to please her husband. I say this for your own benefit, not to put any restraint upon you, but to promote good order and unhindered devotion to the Lord (1 Cor 7.32-5).
In the context, Paul is arguing that remaining celibate and single is preferable to being married, because the single person is able to work for the Lord without the hindrance and encumbrance of a family. Of course, he has no conception that married life is itself bad -- on the contrary, marriage was instituted by God and is very good. But the argument is that, while marriage is good, being single is even better, because you can work for the Lord even more.
This is an important message in some contexts where singles are treated as abnormal or unfulfilled, especially if they remain single into their late 20s, then their 30s, etc. This is also strange to the ears of our general culture, where a fulfilling sex life is seen as practically essential to happy living. Who in the world -- apart from monks and nuns -- practices intention celibacy for the sake of devoting himself to other pursuits? No one, as far as I can tell.
But the Bible doesn't speak that way. Sex is not taken as a necessity for a happy and fulfilled life. Some things, of course, are necessary: food, water, shelter, friendship, etc. But sex is not one of them. In fact, two of the most important and central figures in the Bible -- Jesus and Paul -- were unmarried. For this reason, then, we have to reject the notion that a single person is unfulfilled or unhappy, or that he is missing out on some essential component of life.
The first point I gather from this text, then, is that sex (and so marriage) is not essential for living a good and fulfilled life, in spite of what our culture might tell us. The second point is this: if we should remain single, we nevertheless have to make good use of our time.
I've been reading Augustine lately in research for a class, and I am specifically intrigued by his line of argument in his treatises De Sancta Virginitate [On holy virginity] and De bono coniugali [On the good of marriage]. He emphasizes the point that there is no value merely in remaining celibate; there is nothing especially good about virginity per se. Rather, it is consecrated virginity that can be of great value, because it is an entire life that is dedicated to the service of the Lord, rather than to vain pursuits.
So also in the case of Paul: he does not conceive that the single person is better off because she is free to do whatever she likes without the burden of caring for a family. That is hardly valuable, in Paul's eyes, and is probably a sinful attitude. There's no value in being single if you spend all your time taking vacations and enjoying yourself. Rather, he says that the single person is anxious about the affairs of the Lord. He assumes that if a person decides to remain single, she will dedicate herself to serving the Lord in some way or other, and not merely enjoying herself in this life.
We have to use our time well, then, if we are going to remain single. Of course, we do not all have opportunities to serve the Lord in the same ways. Some of us study for the sake of teaching others for their benefit. Others donate time and money to charitable causes. All of us certainly can pray for each other and for the whole world, and all of us can preach the good news of Jesus to others who are in need of it. But the important thing is that we make good use of our time when we have it.
If singles dedicate their time and energies to the service of the Lord and the community, I think they will find themselves more greatly appreciated and respected by others. Consider this case from Acts:
Now in Joppa there was a disciple whose name was Tabitha, which in Greek is Dorcas. She was devoted to good works and acts of charity. At that time she became ill and died. When they had washed her, they laid her in a room upstairs. Since Lydda was near Joppa, the disciples, who heard that Peter was there, sent two men to him with the request, "Please come to us without delay." So Peter got up and went with them; and when he arrived, they took him to the room upstairs. All the widows stood beside him, weeping and showing tunics and other clothing that Dorcas had made while she was with them. Peter put all of them outside, and then he knelt down and prayed. He turned to the body and said, "Tabitha, get up." Then she opened her eyes, and seeing Peter, she sat up. He gave her his hand and helped her up. Then calling the saints and widows, he showed her to be alive. This became known throughout Joppa, and many believed in the Lord (Acts 9.36-42).
Tabitha was devoted to good works and charity, which means she was likely single and unmarried. And look at how her efforts, unhindered and unencumbered by familial responsibility, were so appreciated by the community: at her death, widows carrying tunics and other garments made by her showed them to the apostle Peter. That is how much they loved her and appreciated what she had done for them.
If you are single and you wish to be appreciated by the community like Tabitha was, then make good use of your time. Paul would insist that your singleness is not an opportunity for you to enjoy yourself before you get married or before you get old; that is a worldly way of thinking. In the meantime, there are people in need, and you are able and ready to help them, if only you want to.