To summarize Ephesians 1: 3-11, Paul discusses how God chose Israel, predestinated them to adoption, redemption, and became the vessels through whom salvation came into the world. The personal pronouns in verses 3-11 are significant because it distinguishes the “we” from the “you” as participants. The Gentiles were being added to the promise of the inheritance. So, verses 12-13 starts with the Jews who first trusted in God but adds, “you also (Gentiles) were sealed with the Holy Spirit of promise.”
What we know of the Ephesians is taken from this letter and Luke’s history of Paul’s work among them as recorded in Acts 19. Luke reveals that when he arrived in Ephesus, he meets twelve disciples whom he asked, ‘Have you received the Holy Spirit since you believed?’ They had not heard that the Holy Spirit was to be given. After Paul taught them the purpose of John’s baptism and the promise of the baptism of the Holy Spirit, they were baptized into the name of Jesus. This same pattern is seen in Peter’s teaching in Acts 2:38-39. After the twelve were baptized, Paul laid his hands on them and they received the miraculous measure of the Holy Spirit and spoke in tongues. In this way, they were sealed with the Holy Spirit of promise. The promise was not automatic but was granted through the laying of an apostles’ hands. It was visible evidence that the Holy Spirit was the power behind them. This miraculous impartation of power was the seal that gave evidence that they were His children. In other words, it was the guarantee of their inheritance.
Seals were used for various purposes. First, the seal was used by princes and kings, and nobles in the time of the Bible as a way of securing it for some future time or for certain readers, only. For example, when Daniel ignored the King’s decree and prayed to God as he had always done in the past, he was thrown into a lion’s den (Daniel 6:16). Before throwing him in the den, the king said to him, “May thy God whom thou serveth continually, rescue you.” Verse 17 explains that a stone was brought in and laid upon the mouth of the den and “the king sealed it with his signet, the signet of his lords, that the purpose might not be changed concerning Daniel.” If someone approached anything with the King’s seal, no one was to tamper with it, and certainly not open it. The highest authority in the land had sealed it and secured it with his personal signet mark. The most common seal was melted wax placed on a scroll that would close it up or seal it. An impression from the ring would identify the authority of the one who bound it.
Another illustration of securing something from tampering is when Jesus was buried in the tomb. A stone was rolled across its entrance and sealed with the seal of Rome. No power should dare open the seal unless it is a power greater than Rome. Of course, a power greater than Rome broke the seal when Jesus came forth from the grave.
The second use of a seal is a sign of authenticity. When Jezebel wrote an official letter, giving all rights of Naboth’s vineyard to Ahab, the letter was sealed (1 Kings 21: 8). This proved that it was a legitimate document from the King, as a royal signature. Once again, the application of this type proves authenticity and anyone thus sealed is an authentic representative of the King.
Another illustration of authenticity is seen when completing a transaction. Jeremiah was told by God to buy a field, not for himself to enjoy but for his descendants who will one day return from the captivity (Jeremiah 32). When Jeremiah bought the land, he sealed the transaction. It is genuine, authentic evidence that the land was bought by Jeremiah.
Similarly, a seal could be used to mark ownership like a brand would, today. Shepherds may mark their flocks to distinguish their own from those of others. True Christians are marked as God’s possession. This mark of ownership is presented in John’s Revelation of Jesus Christ, the Lamb that turned Lion of the tribe of Judah. Some had the mark of the beast, while others were sealed with the blood of Christ. That this seal is particularly involved in the meaning of this text is clear from verse 14 that speaks of God’s “own possession.”