Why is the Lamb worthy to take the scroll and open the seals?
The Lamb is worthy because He was slain and by His blood redeemed people to God out of every kindred, tongue, people, and nation. His worthiness rests on His redeeming work at the cross, the blood by which He redeemed them, fulfilling God's absolute requirement of blood for remission.
Les teaches that the new song in verse 9 declares the Lamb worthy to take the scroll and open its seals because He filled the qualifications: He was slain, a reference to the cross, and He redeemed us to God by His blood. Les emphasizes that His power of redemption has been brought out into the open, and although many today dislike the blood aspect of the Gospel, it cannot be compromised. He connects this to the absolute that without the shedding of blood there is no remission, and that this redemption reaches every kindred, tongue, people, and nation.
And they sung a new song, saying, Thou art worthy to take the book, and to open the seals thereof: for thou wast slain, and hast redeemed us to God by thy blood out of every kindred, and tongue, and people, and nation;