en_tn/rev/07/02.md

the seal of the living God

The word "seal" here refers to a tool that is used to press a mark onto a wax seal. In this case the tool would be used to put a mark on God's people. Alternate translation: "the marker of the living God" or "the stamp of the living God" (See: rc://en/ta/man/translate/figs-metonymy)