Revelation 5  John has described his first glimpse of heaven and now observes a specific, significant event.. that turns into a worship service.

Verse 1.. John sees - a book in the Father's right Hand.  The book or scroll is sealed with 7 seals.
Verse 2.. John hears - " a strong angel" loudly asks, " Who is worthy to open the book and to break the seals." 
Verse 4... John weeps because none are found worthy, until one of the elders comforts him. " Stop weeping; behold, the Lion that is from the tribe of Judah, the Root of David, has overcome so as to open the book and its seven seals." 

Jesus, the Lion,  the Lamb, "standing, as if slain"  appears in the center of the scene.  " And He came, and He took it out of the right hand of Him who sat on the throne." ( v7)

He is worthy!
He overcame. He fulfilled the will of the Father.  He has the right to come and open the book.
Worship breaks out..

The first song is sung by the 4 creatures and the 24 elders.
v9-10  " Worthy art Thou to take the book, and to break its seals; For Thou wast slain, and didst purchase for God with Thy  blood men from every tribe and tongue and people and nation.  And Thou hast made them a kingdom and priests to our God. And they will reign upon the earth." 

The second song adds the voices of myriads of angels!
v12 "Worthy is the Lamb that was slain to receive power and riches and wisdom and might and honor and glory and blessing." 

v13 The third song adds the voices of "every created thing which is in heaven and on the earth and under the earth and on the sea.... To Him who sits on the throne and to the Lamb, be blessing and honor and glory and dominion forever and ever." 

Jesus is worthy.  He is the Lion of Judah and the Lamb that was slain.
He purchased us with His blood.
He makes us a kingdom and priests.
He is worthy of all power, of all miraculous works, of all strength, of all might.
He is worthy of all riches, of all wealth and abundance.
He is worthy of all wisdom, might, honor and glory.
He is worthy of all blessing.

John is privileged to witness this event almost 2000 years ago... yet it is something that hasn't yet happened according to our timeline... for all creation has not yet sung this song.  The seals have not yet been broken.  The day has not yet come.  What a mystery!  How amazing !  Have you ever tried to comprehend what it will be like when "time shall be no more" ?  We will one day add our voices to those of angels and elders and creatures.. singing praises to the Lamb who is worthy!

Father, let us know the glory of Your majesty and the worthiness of the Son!  Fill us with awe and wonder and love for the One who purchased us with His blood and who is worthy to open the book in Your hand.  By Your grace we will join in the worship around Your throne.  Praise the Lord! Amen.