In contrast [to the Old Covenant], the New Covenant has a spiritual means of entrance: one must believe and be saved (Acts 16:31). Therefore, one’s spiritual life is closely connected to the sign of baptism. If baptism indicates an entrance into the New Covenant, then only those devoted to God and trusting in Jesus should be baptized. True circumcision, as Paul preaches in Romans 2:29, is that of the heart, and it is accomplished by the Spirit. In other words, a person today enters a covenant relationship with God not based on a physical act but on the Spirit’s work in the heart.