A seal in the ancient world accomplished three things: it authenticated (this document is genuine), secured (this is closed and protected), and claimed ownership (this belongs to the one whose seal it bears). All three meanings saturate the biblical use. God sets his seal of ownership on believers through the Holy Spirit: "In him you also… were sealed with the promised Holy Spirit, who is the guarantee of our inheritance" (Eph 1:13–14). This divine sealing is the assurance of final salvation — God marks his own as his own, securing them to the day of redemption (Eph 4:30). Circumcision was called a "seal of the righteousness" Abraham had by faith (Rom 4:11). In Revelation, the sealed scroll of judgment is opened only by the worthy Lamb (Rev 5:1–9), and God's servants are sealed on their foreheads before the judgments fall (Rev 7:3).
SEAL, n. [Sax. sæl; L. sigillum.]
1. A piece of metal, stone, or other hard substance, on which is engraved some device or figure, used for making an impression in wax on letters, deeds or other writings.
2. The wax or other substance bearing the impression of a seal, attached to a writing as evidence of its authenticity.
3. That which confirms, ratifies, or makes stable; assurance. "The seal of the Spirit," in theology, is the certain evidence of divine favor and adoption, communicated to believers by the Holy Spirit.
4. Anything which shuts up or makes fast; security against opening.
The biblical doctrine of the "sealing of the Spirit" as assurance of salvation has been either over-claimed or under-appreciated. Pentecostal traditions sometimes treat a "second sealing" or "baptism of the Spirit" as a post-conversion experience evidenced by tongues — which differs from Paul's consistent teaching that all believers are sealed at conversion (Eph 1:13). Meanwhile, Arminian traditions that deny eternal security effectively deny the sealing's permanence — treating the Spirit's seal as a temporary deposit that can be broken. The biblical metaphor is clear: a royal seal does not expire, fluctuate with feeling, or depend on the sealed person's performance. The Spirit seals; God keeps; nothing snatches from his hand (John 10:28–29).
Latin signum (sign, mark) → sigillum (small seal) → Old French seel → "seal"
→ Also: signal, sign, signature, significant — all from signum
Hebrew:
חוֹתָם (chotam, H2368) — seal, signet
→ From חָתַם (chatam, H2856) — to seal, close up, shut
→ Used of: God's seal on Job (Job 9:7), signet ring (Gen 38:18), sealed scroll (Isa 29:11)
טַבַּעַת (tabba'at, H2885) — signet ring (Esther, Joseph, Pharaoh)
Greek:
σφραγίς (sphragis, G4973) — seal, signet; both instrument and impression
→ Used for: circumcision as seal (Rom 4:11), Holy Spirit as seal (Eph 1:13; 4:30),
sealed scroll (Rev 5-8), sealed servants (Rev 7:3-8), foundation of God (2 Tim 2:19)
σφραγίζω (sphragizō, G4972) — to seal, mark, certify, keep secret
• Ephesians 1:13–14 — "You were sealed with the promised Holy Spirit, who is the guarantee of our inheritance."
• 2 Timothy 2:19 — "God's firm foundation stands, bearing this seal: 'The Lord knows those who are his.'"
• Revelation 5:1 — "A scroll written within and on the back, sealed with seven seals."
• Ephesians 4:30 — "Do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption."
• Revelation 7:3 — "Do not harm the earth or the sea or the trees, until we have sealed the servants of our God on their foreheads."
H2856 — chatam (חָתַם): to seal, close up; the act of securing and authenticating with an official seal.
G4973 — sphragis (σφραγίς): seal; authenticates, secures, and marks ownership; the Holy Spirit is God's seal on every believer (Eph 1:13).