WELS affirms that Matthew 28:19 is Christ's explicit command to baptize in the name of the Father, Son, and Holy Spirit. This trinitarian formula is the prescribed form for valid Christian baptism. WELS doctrine teaches that this formula is essential; baptism without the trinitarian invocation is not a valid sacrament. The Small Catechism, received strictly by WELS, teaches that baptism administered 'with water, in the name of the Father and of the Son and of the Holy Ghost' is the sacrament through which God forgives sins and grants eternal life.

WELS strict confessional subscription includes unwavering adherence to the trinitarian formula as the essential form of baptism, following the Book of Concord and Luther's understanding of Christ's command.