Not too long ago, letters and documents were sealed with wax or clay in which was placed an imprint. The “seal” secured the document and identified its owner.
When a person hears the gospel and believes it, the Father seals the believer with the Holy Spirit (2 Corinthians 1:22-23). The Spirit is the symbol that we belong to God in Christ, and our salvation is fully and eternally protected until the redemption of the purchased possession (Ephesians 1:14). The Spirit in the believer is God’s guarantee to keep us saved and to present us as a glorious and holy bride to His Son (2 Corinthians 11:2; Ephesians 5:25-27). The Spirit ensures that the Church will be a godly and virtuous bride to be given in marriage to Christ Jesus at His return.
The word guarantee is the Greek word arrhabon, meaning down-payment. It’s the modern Greek word used for an engagement ring, which is a down payment or promise that a marriage will take place. The down-payment God has given us is the indwelling Holy Spirit Himself (Romans 8:9, 16) guaranteeing that every promise Jesus has made to His Church will be fulfilled in Heaven.
In Christ you also trusted, after you heard the word of truth, the gospel of your salvation; in whom also, having believed, you were sealed with the Holy Spirit of promise, who is the guarantee of our inheritance until the redemption of the purchased possession, to the praise of His glory (Ephesians 1:13-14).