You say that an LDS marriage has to be in a Mormon Temple to be valid in heaven.
In the Old Testament, the Jews did not go to the Tabernacle or the Temple to get married. Is the LDS Temple supposed to be like the Old Testament Temple or is something completely different?
I haven't seen anything in writing, but Adam and Eve were married for eternity in he Garden of Eden according to Mormonism.
Extra biblical teachings:
As Michael, the archangel, Adam led the forces of God against the armies of Lucifer in the War in Heaven. Under the direction of Elohim and Jehovah, he assisted in the creation of the earth. After taking physical bodies, Adam and Eve brought mortality into being through partaking of the fruit of the tree of knowledge of good and evil. With the fall of our first parents came blood and posterity and probation and death, as well as the need for redemption through a Savior, a “last Adam.” (
1 Cor. 15:45.) To Adam the gospel was first preached, and upon him the priesthood was first bestowed. From Adam and Eve the message of the gospel of salvation went forth to all the world. Following his death, which occurred almost a millennium after he entered mortality, Adam’s watch-care over his posterity continued. Revelations have come and angels have ministered under his direction. Priesthood has been conferred and keys delivered at his behest.
The Man Adam - ensign
Adam was the first man to hold the keys of the everlasting priesthood on earth. With regard to the presidency of that priesthood under Jesus Christ, “Father Adam stands at the head, so far as this world is concerned,” said President Wilford Woodruff.
17 Adam and Eve were married, and since they were married by God when they were immortal beings, their marriage was eternal in nature. President Spencer W. Kimball wrote:
...“‘And I, God, said unto mine Only Begotten, which was with me from the beginning: Let us make man [not a separate man, but a complete man, which is husband and wife] in our image, after our likeness; and it was so’ (
Moses 2:26). What a beautiful partnership! Adam and Eve were married for eternity by the Lord. Such a marriage extends beyond the grave. All peoples should call for this kind of marriage.”
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“‘And I, God, said unto mine Only Begotten, which was with me from the beginning: Let us make man [not a separate man, but a complete man, which is husband and wife] in our image, after our likeness; and it was so’ (
Moses 2:26). What a beautiful partnership! Adam and Eve were married for eternity by the Lord. Such a marriage extends beyond the grave. All peoples should call for this kind of marriage.”
18
“In the Beginning”: - ensign
You can also read that priesthood authority is needed to bestow the ordinance here in the Doctrine and Covenants:
Doctrine and Covenants 132
Section 132, Marriage: An Eternal Covenant