What does Ephesians 1:13 mean?
Paul describes three things that took place in the lives of the Ephesian believers. First, they heard the gospel, known as the word of truth (2 Timothy 2:15; James 1:18).Second, rather than rejecting the message as many Jews had done, these Gentile believers both heard and believed the gospel and were saved as a result (Romans 10:9; Ephesians 2:8–9).
Third, Paul noted that when they became believers they "were sealed with the promised Holy Spirit." This specific description of the Holy Spirit is only used in the book of Ephesians here, and in Ephesians 4:30, among a dozen total references to the Spirit in the letter. A "seal" was a mark indicating a letter or scroll was closed, or completed. When a king or dignitary wanted to show an identifying mark with a letter, he would seal it with a resin imprint of his ring. The Holy Spirit likewise shows that believers belong to the Lord.