The Catechism of the New Apostolic Church

8.3.8 Holy Sealing as an act of God

Like Holy Baptism with water, Holy Sealing is also an act of God upon a human being. That which was begun in Holy Baptism is completed in Holy Sealing, namely the rebirth out of water and Spirit. Both sacraments are acts of God's grace upon a human being and are only performed once. The life received thereby is nourished and preserved above all by regularly partaking of Holy Communion.

The new creation (2 Corinthians 5: 17) which comes into being through the rebirth is a reference to the sanctification and renewal which occurs through God, the Holy Spirit.