Forever isn't long enough
"Members of the Church believe that marriages performed in temples are “sealed,” or blessed to last for eternity. The concept that the family unit can continue beyond the grave as a conscious, loving entity, with the marriage partnership and parent-child relationships intact, is a core belief of members of The Church of Jesus Christ of Latter-day Saints...
According to research cited in a 2000 article in the Los Angeles Times, “in an era of divorce, Mormon temple weddings are built to last,” with only a 6 percent divorce rate. Another study, published in 1993 in Demography Magazine, concluded that members of The Church of Jesus Christ of Latter-day Saints who marry in one of the Church's temples are the least likely of all Americans to divorce."
What is marriage?
"Marriage, in its truest sense, is a partnership of equals, with neither person exercising dominion over the other, but with each encouraging, comforting, and helping the other.
Because marriage is such an important relationship in life, it needs and deserves time over less-important commitments. Couples can strengthen their marriage as they take time to talk together and to listen to one another, to be thoughtful and respectful, and to express tender feelings and affection often.
Marriage partners must be loyal to one another and faithful in their marriage covenants in thought, word, and deed. The Lord has said, “Thou shalt love thy wife with all thy heart, and shalt cleave unto her and none else” ( D&C 42:22). The phrase “none else” teaches that no person, activity, or possession should ever take precedence over the marriage relationship."
What is a Temple Marriage?
"Being married in a temple means being together for all time and all eternity and having an eternal family. When a couple is sealed to each other on earth (with the proper authority) they are also sealed to each other in heaven. Through this sealing power families can be together, after death, in the next life. For a marriage to be eternal a couple must be sealed together in God's holy temple and by his holy priesthood power, if not their marriage will only be 'until death do you part.'
The Celestial Kingdom is where God lives. To be exalted to the highest order of this kingdom a person must receive the sacred sealing ordinance of marriage.
For a temple marriage to remain in effect after this life a husband and wife must remain faithful to each other and their covenants. This means building a marriage founded upon the gospel of Jesus Christ, by following his example and living his teachings.
After a couple are sealed in the temple any children they have (after their sealing) are automatically sealed to them when they are born. If a couple already has children (before being sealed to each other in the temple) those children accompany them to the temple and are sealed to their parents right after the husband and wife are sealed together."
THE FAMILY: A PROCLAMATION TO THE WORLD
"HUSBAND AND WIFE have a solemn responsibility to love and care for each other and for their children. “Children are an heritage of the Lord” (Psalm 127:3). Parents have a sacred duty to rear their children in love and righteousness, to provide for their physical and spiritual needs, and to teach them to love and serve one another, observe the commandments of God, and be law-abiding citizens wherever they live. Husbands and wives—mothers and fathers—will be held accountable before God for the discharge of these obligations.
THE FAMILY is ordained of God. Marriage between man and woman is essential to His eternal plan. Children are entitled to birth within the bonds of matrimony, and to be reared by a father and a mother who honor marital vows with complete fidelity. Happiness in family life is most likely to be achieved when founded upon the teachings of the Lord Jesus Christ. Successful marriages and families are established and maintained on principles of faith, prayer, repentance, forgiveness, respect, love, compassion, work, and wholesome recreational activities. By divine design, fathers are to preside over their families in love and righteousness and are responsible to provide the necessities of life and protection for their families. Mothers are primarily responsible for the nurture of their children. In these sacred responsibilities, fathers and mothers are obligated to help one another as equal partners. Disability, death, or other circumstances may necessitate individual adaptation. Extended families should lend support when needed."
Keep in mind that in The Family: A Proclamation to the World, it is stated that "marriage between a man and a woman is ordained of God and that the family is central to the Creator’s plan for the eternal destiny of His children." Now while I believe that with all my heart, I neither condemn nor condone marriage of anyother kind. It is not my place to say who can and cannot marry. However, such a marriage is limited to an "until death do you part" marriage. I love my wife so very much that the thought of losing her to death is unbearble. Getting sealed in the temple to her and our daughter is a thought that brings me great joy. I have never been happier in my entire life.