Why was no one able to open the scroll in Revelation 5?
No one was able to open the scroll because it represented a sealed mortgage requiring a qualified next of kin who possessed the wherewithal and willingness to redeem it. Since no one in heaven, earth, or under the earth met those requirements, none was found worthy, and John wept.
Les explains that the scroll is pictured as a mortgage sealed with seven seals. In ancient Israel, property could be redeemed by a next of kin who had the wherewithal and was willing to pay off the mortgage, so the family could keep its inheritance. The private details were written inside, while the public ownership details were written outside. In the same way, no man in heaven, in earth, or under the earth was able to open the scroll, because no one seemingly had the next of kinship, the wealth, or the willingness. John wept much because no one was found worthy to open, read, or look upon the scroll.