5:2And I saw a strong angel proclaiming with a loud voice, "Who is worthy to open the book and to break its seals?"

And I saw a STRONG ANGEL proclaiming with a loud voice,

This angel was one with great authority like a Gabriel perhaps. "Proclaim" means to broadcast forth; from the next verse, it is implied that this proclamation was to the physical universe as well as the spiritual universe.

"WHO is WORTHY to open the book and break its seals?"

Under Jewish law, to redeem "sold" property, it had to be a kinsmen and a Redeemer. That is, a person who was related and had the means (money) to pay the price. Spiritually, it was One who was our brother (human) and paid the price.

Note: none of the Biblical saints or even present day church leaders or television preachers could open the book because they were/are NOT the owner. Recall the owner was written on the outside of the scroll.

If the book with these seals contains the judgment "of things to come" then according to John 5:21-27, the Son is both kinsmen (becoming human) and owner. Removing the "squatters" from this earth comes with the rights of ownership, Psalm 2:7-9.