In the midst of the fulfisment of the Kingdom stands Christ’s command of universal baptism. This baptism is the royal sign of the richness of the Kingdom at hand. The institution of this sign is preceded by the royal proclamation: “All authority hath been given unto me in heaven and on earth” (Matt. 28:18). Just as John’s baptism had raised questions about his qualifications, so now Christ’s qualification stands in focus. Before the Ascension Christ gives the sign of God to the Church, a sign of particular power through his divine institution and his involvement with the Kingdom.
– G.C. Berkouwer, Studies in Dogmatics: The Sacraments, pg. 101