Revelation 1:3
Blessed is he who reads and those who hear the words of this prophecy, and keep those things which are written in it; for the time is near.

The Book of Revelation offers a particular and unique blessing to those who read and keep the message of this book.

Fortunately, John didn’t say that we had to understand everything in the Book of Revelation to be blessed. There are some difficult things in this book, that may only be understood as we look back at fulfilled prophecy. But we can be blessed by reading and hearing even when we don’t understand.

Revelation 14:13
And I heard a voice from heaven saying unto me, Write, Blessed are the dead which die in the Lord from henceforth: Yea, saith the Spirit, that they may rest from their labours; and their works do follow them.

We can only imagine what courage and comfort this passage will give embattled, persecuted saints during the Great Tribulation. Clearly, God wants to encourage His people to be steadfast in times of trial, focused on what blessed rest and reward awaits them in eternity.

Revelation 16:15
Behold, I am coming as a thief. Blessed is he who watches, and keeps his garments, lest he walk naked and they see his shame.

In the midst of the description of the coming battle, there is a warning to be prepared in light of Jesus’ assured victory.

Garments are pictures of spiritual and practical righteousness. We are given the righteousness of Jesus as a garment (Galatians 3:27), but we are also called to “put on” the nature of Jesus in terms of practical holiness (Ephesians 4:20-24). Above all, we must not be “naked” - that is, without a covering, or trying to provide our own covering like Adam and Eve (Genesis 3:7), which is like filthy rags in the sight of God (Isaiah 64:6).

Revelation 19:9
Then the angel said to me, "Write: 'Blessed are those who are invited to the wedding supper of the Lamb!' " And he added, "These are the true words of God."

Blessed indeed; Jesus Himself eagerly anticipates this marriage supper. He spoke longingly of the day when He will drink of the fruit of the vine again, with His disciples in the kingdom (Matthew 26:29).

Revelation 20:6
Blessed and holy is he who has part in the first resurrection. Over such the second death has no power, but they shall be priests of God and of Christ, and shall reign with Him a thousand years.

This is a resurrection of blessing (blessed and holy is he)
This is a resurrection of power (over such the second death has no power)
This is a resurrection of privilege (they shall be priests of God . . . shall reign with Him a thousand years)

Revelation 22:7
Behold, I am coming quickly! Blessed is he who keeps the words of the prophecy of this book.”

This blessing reminds us that prophecy gives us a word to keep, not merely material for interesting discussions and debates. The main intent of prophecy is to lead us to trust and obey God, and apply His truth to the way we live.

Revelation 22:14
Blessed are those who do His commandments, that they may have the right to the tree of life, and may enter through the gates into the city.

Doing His commandments does not earn us eternal life, but it is evidence that we have been granted eternal life. Besides, there is an inherent blessing in doing His commandments, because they are good and right for us.

Regarding the phrase those who do His commandments some translations have those who have washed their robes instead. The difference is between two ancient Greek words:
HOIPLUNONTESTASSTOLAS (washed their robes) or
HOIPOIOUNTESTASENTOLAS (do His commandments)
This is a good example of how a copyist’s error can cloud a text in rather minor ways, without effecting the essential meaning of the context.