Revelation 5:4

4 And I wept much, because no man was found worthy to open and to read the book, neither to look thereon.

By what John wrote in his other books of the New Testament he knew salvation would come through Jesus so we might wonder why John wept. While salvation through Jesus was clear to John, he understood that the restoration of earth could not come about until a worthy  man  was found to open the book. Until the time a worthy man was found, Satan would continue to reign and sin and death would continue on the earth. He knew that Jesus was God; that is evident in his gospel and epistles - but John must not have understood that Jesus as a man (born of the seed of a women) was qualified to fulfill the role of kinsman redeemer.