"What I mean, brothers and sisters, is that the time is short. From now on those who have wives should live as if they do not; those who mourn, as if they did not; those who are happy, as if they were not; those who buy something, as if it were not theirs to keep; those who use the things of the world, as if not engrossed in them. For this world in its present form is passing away." NIV translation
What Paul is reminding them of is that the things of this world are temporary and it is time for believers to get and stay focused on lasting things.
"I would like you to be free from concern. An unmarried man is concerned about the Lord's affairs - how he can please the Lord. But a married man is concerned about the affairs of this world - how he can please his wife - and his interests are divided. An unmarried woman or virgin is concerned about the Lord's affairs: Her aim is to be devoted to the Lord in both body and spirit. But a married woman is concerned about the affairs of this world - how she can please her husband." NIV translation
Anyone who has tried to balance their family life with work and the things of God can readily understand what Paul is saying here. With the wife usually comes a family and taking care of them which takes work and time. There are only so many hours in a day and so the day has to be divided between responsibilities to family and service to others which is our calling in the Lord. The same principle applies to women as, whether they earn an income or raise a family and take care of the home, they also only have so many hours in a day.
"I am saying this for your own good, not to restrict you, but that you may live in a right way in undivided devotion to the Lord." NIV translation
Paul is telling us that we are free to marry as marriage was given by God. Some have misunderstood this teaching and so have made it a requirement for men and women serving God to remain celebate.