Revelation 19:9: And he saith unto me, Write, Blessed are they which are called unto the marriage supper of the Lamb. And he saith unto me, These are the true sayings of God.

After the marriage of the Lamb on mount Zion in heaven¹ there will be a separate celebratory wedding feast on earth² called the marriage supper of the Lamb.³ John's symbolism follows the Jewish custom⁴ where the supper takes place separately after the marriage ceremony is complete.⁵ Christ used similar Jewish customs in the related parables of the ten virgins in Matthew 25⁶ and the marriage of the king's son in Matthew 22.⁷

The marriage supper of the Lamb will literally occur on earth at New Jerusalem in Missouri⁸ at the time of Christ's sudden appearance to his temple in that location.⁹ For this to occur at the time of the Second Coming, the saints that are worthy to attend the marriage supper must first build the temple at Independence during the Great Tribulation, which is the last 3½ years before the marriage supper occurs.¹⁰

At the marriage supper, Christ will drink the fruit of the vine, which is to say that he will partake of the sacrament¹¹ with his disciples who are the elect of God.¹² This will fulfill the prophecy Christ made to his ancient apostles at the last supper when he instituted the sacrament among them.¹³ The rich, learned, wise, and noble people of all nations are invited to this sacrament meeting.¹⁴ However, among the many that are called to attend, only the symbolically poor, lame, blind, and deaf will attend and be admitted to the marriage supper.¹⁵ In other words, the guests will be the humble and meek people that accept the gospel through baptism¹⁶ and are worthy of celestial glory.¹⁷ The poor and meek do not have to be exaltation-worthy since there will be guests that attend the marriage supper who are not the bride.¹⁸ Anyone that qualifies for exaltation is figuratively the bride.¹⁹ The guests, on the other hand, need only qualify for the celestial kingdom as unexalted ministering angels.²⁰

Many people will never be worthy to attend the marriage supper, even though the Lord calls on, and invites, everyone to do so.²¹ The Lord's invitation to prepare for the wedding supper is so important that John's angelic guide from Revelation 17:1²² told him in Revelation 19:9 to write the following words exactly, saying:²³ "Blessed are they which are called unto the marriage supper of the Lamb."²⁴ This is the fourth of seven beatitudes in the Book of Revelation.²⁵

The angel emphasized the absolute certainty of everything he had shown and described to John since Revelation chapter 17,²⁶ including the certainty of both the blessings and cursings,²⁷ by telling John that: "These are the true sayings of God."²⁸ The sayings must all come to pass because they come from God the Father who cannot lie.²⁹

Isaiah 25:6 calls the marriage supper of the Lamb the "feast of fat things."³⁰ Doctrine and Covenants Section 58:11 calls it the supper of the house of the Lord.³¹ The latter name alludes to those saints that attend the marriage supper as a bride because they make and keep sacred temple covenants.³²

Many wicked people who are unqualified to attend the marriage supper will be destroyed when Modern Babylon falls during the Third Woe.³³ The fouls of the air will devour their dead bodies during another, and entirely separate, feast called the supper of the Great God in Revelation 19:17-18.³⁴