It is not unusual for those who oppose baptismal regeneration to often slip into language and concepts that are utterly inconsistent with their purely symbolic understanding of baptism; John Calvin and other figures who opposed the doctrine displayed such an inconsistency, as do many modern Reformed authors. Notice the following, which is classical “speaking from both sides of one’s (theological) mouth":
Brannon Ellis, “Union with Christ as the Covenant of Grace,” in Sanctification: Explorations in Theology and Practice, ed. Kelly M. Kapic (Downers Grove, Ill.: IVP Academic, 2014), 79-102, here, pp. 84. 85; comment in square bracket my own.
The benefits communicated to us in baptism, as [the Belgic and Heidelberg catechisms] describe them, come to us only because of Christ, but they do not come from a Christ “who remains outside of us,” as Calvin argued. Both the new status and the new birth signified and sealed in baptism belong to the Reformed emphasis on the “double grace” of justification and sanctification enjoyed in union with Christ . . . At the same time, the Reformed tradition has emphasised the clear role that baptism plays as a sacrament of initiation into the Abrahamic covenant of grace under its new covenant administration (the church, inclusive of Gentiles as well as Jews). In baptism the many are incorporated into one body (Eph 4:4) and begin to participate in the life of the age to come as those who have put on the resurrected and glorified Jesus and are being conformed to the same image (Rom 4:11; 1 Cor 12:12-13). Entrance into new life in Christ the head of his body is entrance into the life of the members that receive life from and in their head (Eph 1:22-23; 2:21; Col 1:18). Though experiencing baptism does not of itself save--and though the Spirit’s effective working through the sacrament is not limited to the time of its administration (so Westminster Confession of Faith 28.6)--Christian baptism if never something merely nominal nor is it legitimately administered beyond the manifest realm of Christ’s saving work and kingly rule.
Brannon Ellis, “Union with Christ as the Covenant of Grace,” in Sanctification: Explorations in Theology and Practice, ed. Kelly M. Kapic (Downers Grove, Ill.: IVP Academic, 2014), 79-102, here, pp. 84. 85; comment in square bracket my own.