Holy Sealing is the sacrament through which God Himself shares His nature and life: through the laying on of hands of an apostle, the believer receives the gift of the Holy Spirit. The prerequisites for Holy Sealing are belief in the triune God, proper baptism with water, as well as belief in the apostles sent by Jesus Christ.
This baptism with the Spirit completes the rebirth that was begun in Holy Baptism and makes us into a new creation. Through this rebirth, we enter into childhood in God, which means we recognize and accept God's call for our lives, receive the sacraments, believe in the gospel, and orient our lives to the return of Christ.
For more information on the sacrament of Holy Sealing, see the Catechism of the New Apostolic Church (CNAC) section 8.3