From another revelation to the Prophet Joseph, we learn that there are three degrees within the celestial kingdom. To be exalted in the highest degree and continue eternally in family relationships, we must enter into “the new and everlasting covenant of marriage” and be true to that covenant. In other words, temple marriage is a requirement for obtaining the highest degree of celestial glory.
The answer asserts that according to LDS, in order for exaltation to be achieved, it is necessary to enter the "eternal covenant of marriage" and that the unmarried cannot achieve exaltation. My understanding is that, in order to enter into that eternal covenant, one must undertake an earthly marriage administered through a proper authority in the temple. Therefore it appears that, in order to achieve exaltation it is necessary to be married on earth:
Our exaltation depends on marriage, along with other principles and ordinances, such as faith, repentance, baptism, and receiving the gift of the Holy Ghost. We believe that marriage is the most sacred relationship that can exist between a man and a woman. This sacred relationship affects our happiness now and in the eternities. - Eternal Marriage
Additionally, it is stated that the advent of the Gospel's Restoration (as revealed to LDS Apostles) has restored this eternal covenant of marriage:
Adam and Eve were married by God before there was any death in the world. They had an eternal marriage. They taught the law of eternal marriage to their children and their children’s children. As the years passed, wickedness entered the hearts of the people and the authority to perform this sacred ordinance was taken from the earth. Through the Restoration of the gospel, eternal marriage has been restored to earth. - same link as above
In 1 Corinthians chapters 7-9, the Apostle Paul has much to say on the matter of marriage (too much to copy and paste here). His message to the unmarried is that, since the advent of the Gospel age, it is better to remain unmarried. He does neither forbid marriage nor disdain marriage but recognizes it as necessary for those who "cannot contain":
I say therefore to the unmarried and widows, It is good for them if they abide even as I. But if they cannot contain, let them marry: for it is better to marry than to burn. - 1 Corinthians 7:8-9
The reason he gives for the unmarried state on earth to be preferable is that the married are distracted (and rightly so) by the needs of the marriage and the marriage partner. A married person is unable to be solely dedicated to the Lord's work because of what a marriage entails and requires:
But I would have you without carefulness. He that is unmarried careth for the things that belong to the Lord, how he may please the Lord: But he that is married careth for the things that are of the world, how he may please his wife. There is difference also between a wife and a virgin. The unmarried woman careth for the things of the Lord, that she may be holy both in body and in spirit: but she that is married careth for the things of the world, how she may please her husband. And this I speak for your own profit; not that I may cast a snare upon you, but for that which is comely, and that ye may attend upon the Lord without distraction. - 1 Corinthians 7:32-35
And in regards to the father of the unmarried woman Paul writes that if the virgin requires it he may let them marry...it is not a sin, but:
But if any man think that he behaveth himself uncomely toward his virgin, if she pass the flower of her age, and need so require, let him do what he will, he sinneth not: let them marry. Nevertheless he that standeth stedfast in his heart, having no necessity, but hath power over his own will, and hath so decreed in his heart that he will keep his virgin, doeth well.So then he that giveth her in marriage doeth well; but he that giveth her not in marriage doeth better. - 1 Corinthians 7:36-38
In summary, Paul makes it clear that earthly marriage is not wrong but that, now that the gospel age has commenced, the unmarried state is spiritually preferable if has has been so gifted (v. 7).
LDS says marriage is spiritually necessary and Paul says it is spiritually better to remain unmarried. According to LDS, is Paul wrong?