"And cried with a loud voice, saying, Salvation to our God which sitteth upon the throne, and unto the Lamb." (Revelation 7:10)

In "Biblical Perspective" R.E. Trotter writes:

Although the world is rocking and reeling and its very foundations are crumbling at the center of the universe, God's eternal throne is still as solid and secure as ever. God is sovereign, and the Lamb is still Savior, and everything is under perfect control. Whereas Jesus was referred to as a Lamb once in the Old Testament (Isa. 53:7), twice in the Gospels (John 1:29, 36), and once in the Epistles (1 Peter 1:19), He is referred to as the Lamb twenty-eight times in the Book of Revelation. We have to conclude that it is a book of salvation available to the very end.

Source: Christ, the Triumphant Lord: Adult Teacher's Insights, page 45.