In the Houses of the Lord scattered across the Earth, the fact is that the LDS Church DOES have the Authority to marry forever because God said in the beginning to the first man and the first woman that He had "created man in his own image, in the image of God created he him; male and female created he them. And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth (Gen 1:28)". And also Jesus says, "What God hath joined together let not man put asunder (Matt 19:6)." We are the only religion in the world to teach that man and woman can live forever as husband and wife.
President Jedidiah M. Grant saw the Spirit World for two nights in succession before he died. President Grant told President Heber C. Kimball of the vision. President Heber C. Kimball quoted Grant as saying, "To my astonishment when I looked at families there was a deficiency in some, there was a lack, for I saw families that would not be permitted to come and dwell together, because they had not honored their calling here. (JD 4:136)" The "calling" which the families did not honor begins in the House of the Lord when the New and Everlasting Covenant of Marriage is entered into. The only way to be united as a family for eternity is within The Church of Jesus Christ of Latter-day Saints.
Thus saith Jesus Christ, "Search the Scriptures, for in them ye think ye have eternal life. And they are they which testify of Me."
- John 5:29
In the Name of Jesus Christ, Amen!