What is the context?
Paul now speaks directly to his readers: they too have heard the word of truth, the gospel of their salvation, and believed in Christ. He includes them in the blessing he has been describing.
They were sealed with the promised Holy Spirit. Thayer’s entry for sealing explains this use as God marking out His people through the gift of the Spirit. The image expresses belonging to Him.
The Spirit is also the pledge of their inheritance. The Greek word is ἀρραβών, arrabōn (ah-rah-BOHN), a down payment that pledges the full amount to come. Thayer’s lexicon identifies the Spirit’s gift here as both a foretaste and a pledge of future blessing.
Paul connects this gift with the coming redemption of those who are God’s possession. Their present life through the Spirit points toward what God will complete. The repeated purpose of the whole blessing returns once more: praise of His glory.
How is this passage commonly understood?
Christians commonly understand the Spirit as God’s gift marking His people and assuring them of the inheritance to come. They explain the sealing and its relation to faith, baptism and assurance in different ways.
The Catholic USCCB note on verse 13 connects the sealing with baptism. The Catechism, paragraphs 1272–1274, describes baptism’s permanent mark of belonging to Christ, while distinguishing that mark from sin’s ability to prevent the fruits of salvation. Paragraphs 1295–1296 also connect the seal of the Spirit with confirmation.
Wesley’s notes on verses 13–14 understand sealing in terms of God’s image impressed on the soul and fuller assurance of His promises, possibly after the first coming to faith. A different account of assurance appears in Dallas Theological Seminary’s statement, article X, which grounds the lasting security of every true believer in God’s purpose and the Spirit’s abiding presence. These are the teachings of the sources named, rather than one explanation shared by all Christians.
Where does this fit in God's plan?
2 Corinthians 5:1–5 also names the Spirit as God’s pledge. There Paul is speaking about mortal life being swallowed up by life and God preparing His people for that future.
That explicit connection gives a concrete horizon to the inheritance described here. The Spirit’s presence now belongs to God’s purpose of bringing His people into the life He has prepared, including the overcoming of bodily mortality.
What is our position?
Our study Baptism, in its discussion of Ephesians 4:30, describes the Spirit as indwelling the believer at salvation. It distinguishes grieving Him through sin from ending that relationship: the study does not understand unconfessed sin as driving the Spirit away. Its emphasis is on honest confession and restored fellowship with God.