And he said to me, "Write, `BLESSED are those who are invited to the MARRIAGE SUPPER of the LAMB.'
The speaker probably is the angel in Revelation 17:1 who had shown John the destruction of Babylon (materialism globally). He goes on to show the other side: the MARRIAGE SUPPER of the LAMB. The sight must be so awesome that John is standing there grasping for anything he can relate this to. Apparently, he can't find anything so beautiful, and so the angel has to remind him again to "WRITE" (Revelation 1:11,19).
This "BLESSED" is the fourth one in the Revelation (see the list in Revelation 1:3). There is variance among scholars as to whom are the invited. Some suggest that the BRIDE is not at the MARRIAGE SUPPER. In Jewish weddings, the bride was brought to the groom at the end of the MARRIAGE SUPPER. So the invited must be guests. Interpreting this says that the believers saved under grace, i.e. after Christ's resurrection and up to the rapture are not the ones invited. That would leave pre-Christ's resurrection and after rapture believers as the invited. This distinction may be reading too much into this verse; rather, it probably means the invited are those who have attained salvation regardless for age period. God doesn't want any to perish (2 Peter 3:8-9-13) and the MARRIAGE SUPPER is for the living. Furthermore, Jesus in Matthew 8:5-11-13 indicates there is no distinction between Jews or Gentiles at the SUPPER. This doesn't take anything away from the status the Jews hold as God's chosen people.
In a sense, everyone is invited to the SUPPER as everyone's name is written in the book of life to begin with. We choose to "uninvite" ourselves by having our name erased from the book of life (Revelation 3:5). Our actions or life style or life motivations then indicate our choice (James 4). If we choose to be an enemy of God, then we certainly aren't going to be invited to the MARRIAGE SUPPER. The SUPPER is for the cleansed (previous verse) and the righteous. The invitation is the knock on the 'church' door (Revelation 3:20).....we choose to answer the knock or not.
And he said to me,"These are TRUE WORDS OF GOD."
This seems so obvious to us, but John has seen and written about so much caused by the devil or deceiver (Revelation 12:9), that he may have wondered whether this MARRIAGE SUPPER is one of the devil's deceptions (Mark 13:14-22-23). Thus it is entirely appropriate for the angel to confirm that the invitation to the MARRIAGE SUPPER is authentic and from God.
This expression is used twice more in the Revelation (Revelation 21:5 and Revelation 22:6). Heaven must be so awesome and different due to the absence of evil that John has to be assured that this is NOT a deception. All uses of this expression surround glimpses of the new heaven.