What is the significance of being sealed with the Holy Spirit?

In Ephesians 1:13-14, Paul explains that believers are sealed with the Holy Spirit of promise as a guarantee of their inheritance in Christ. This sealing is significant as it indicates that the Holy Spirit is both a mark of ownership and a promise of God's faithfulness. The presence of the Holy Spirit in the life of a believer assures them of their salvation and keeps them secure in their relationship with God. This divine seal serves as a reminder that their salvation is irrevocable and that they belong to God forever, culminating in the full realization of their inheritance in heaven.