Jesus is worthy to open the seals because He was slain and has redeemed believers by His blood.
The worthiness of Jesus to open the seals and implement God's kingdom plan is rooted in His sacrificial death. Revelation 5 reveals that the Lion of the tribe of Judah, who is also the Lamb that was slain, has overcome and is thus qualified to take the book from God's right hand. His redemptive work has satisfied God's justice by paying the price for sin, which allows Him to usher in God's perfect kingdom. The contrast between the mighty Lion and the sacrificial Lamb illustrates the dual nature of Christ's mission—both powerful and humble. Only through His blood can believers be redeemed and made kings and priests unto God.
Commentary