The use of a seal as a sign of ownership, approval, or authentication is very ancient, and is found across many cultures. The earliest archaeological reference I could find is Chinese, about 3000 years BC. Carved into wood or stone, proprietary symbols were impressed on wax, clay, or later, on paper with ink or dye.
In the Indus Valley, merchants used a seal to identify their trade goods.
In the ancient Middle East, Mesopotamian peoples used an engraved cylinder, and Egyptians a signet ring to make these impressions.
The elite of conquering Greek and Roman forces amassed impressive collections of these seals, thought to be symbolic of their having assumed the power and authority of the former owners.
The understanding of a seal is unusual for its uniformity across such diverse cultures, and its similar employment in modern times, for legal documents, or certification of approval by recognized organizations or authorities.
Unlike many artifacts of culture, the use of a seal, as biblically referenced, is therefore not unique to first century Greek or Roman culture, nor to Hebrew tradition, where it is noticeably rare. In fact, many of the LXX references are to seals used for official edicts by foreign kings (in Esther and Daniel), to people exercising the authority of rulers (Jezebel in I Ki.20), and to specifications for the regalia of the Jewish high priest (Ex.28,35,36). Isaiah (29:11) and Daniel (8:26, 9:24, and 12:4,9) are told to “seal” (conceal) a word of prophecy until a designated time. Deut.32:34 and II Ki.22:4 refer to the securing of a treasury. In the Song of Solomon (4:12, 8:6) it appears to be a term of endearment – perhaps also in Hag.2:24?. A legal deed to land is “sealed” as well (Jer.39:10, 11, 25, 44).
For the verb, sphragizo, L/S lists “to close or enclose with a seal, to authenticate a document, to certify an object after examination, to seal (mark) an article to show that it is pledged, to accredit an envoy, to confirm or set a seal of approval on, to set an end or limit.” Bauer adds “to secure something so as not to be disturbed, to keep secret, to mark as a means of identification of ownership.”
The noun form, sphragis, refers to “a seal or signet, a gem or stone for a ring, a warrant, a mark of ownership, a wound or blow, a governmentally defined and numbered area of land” (L/S), “the certification of a last will and testament, a sign or stamp of approval, that which confirms” (Bauer), with the additional note that some second century writers used sphragis as a synonym for baptism.
Many of these ideas appear in the New Testament uses of the words. Clearly, the “seal/sealing” referenced in Rv.7:2,3,4, is a mark of identification, of God’s “ownership” of his people, in contrast to his opponents mentioned in 9:4. This identification also affords protected status to those who are so identified, as is apparent as well in II Cor.1:22, Eph.1:3, 4:30; and II Tim.2:19, despite the chaos and destruction that may also surround the people concerned.
The seal placed on Jesus’ tomb (Mt.27:66), on the other hand, was intended to keep anyone from meddling with the body. (The authorities mistakenly thought that it would keep him IN – like the seal (Rv.20:3) on the pit where Satan and his minions are confined.)
The seals of the “little book” [scroll] in Rv.5, 6, and 8:1, however, which could only be opened by the eminently qualified Lamb, in addition to securing its wrapper, were obviously to restrict, but not to prohibit, access to its contents. This is reminiscent of the instructions to Isaiah and Daniel mentioned above, to “seal up” particular elements of prophecy until the proper time, which instructions were repeated to John regarding what he had heard in the thunder (Rv.10:4). In contrast, the Revelation ends with the admonition NOT to “seal” [keep secret] the information he had been given, because “the time is near” and these were instructions that folks were going to need for their present circumstances.
The sense of certification of authenticity comes through in Paul’s concern for the safe and responsible delivery of the relief offering to Judea (Rom.15:28), and his reference to the brethren in Corinth as “the seal of my apostleship” (I Cor.9:2) – they themselves constitute the evidence they are seeking that his work is genuine, and that he is the Lord’s accredited envoy.
In a similar vein, John observes that a person who pays attention to Jesus has thereby contributed his own certification [seal] that God is real / true / genuine (Jn.3:33), and in 6:27, that God the Father has granted his personal credential [seal] to his Son, enabling him to bestow on his faithful followers “the food that remains [endures] for eternal life.”
And just as circumcision became for Abraham (Rom.4:11) God’s “seal” [certification] of their relationship, so for faithful followers of Jesus (Eph.1:13 and 4:30), the promised Holy Spirit becomes the mark of God’s ownership, as well as the “down-payment” on their inheritance as his sons.
After a series of warnings about the very real dangers posed by deceptive teachers, Paul reminds his young assistant, Timothy, (II Tim.2:19), “But God’s foundation is still solid! It has this guarantee [seal] – “The Lord knows who belongs to him! And everyone who claims the Lord’s name must stay away from injustice!”
Here, then, in simple summary, is the evidence of God’s “seal” of ownership, approval, and authority:
- the Lord himself knows who belongs to him
- he has identified and empowered them by the gift of his Holy Spirit
- they are recognizable, both within and from outside their company, by their practice of, and devotion to, his justice.
Beyond that, we need not – and dare not – make further claim or requirement.