TE Stellman: To that end, how would you respond to the language of the indictment’s first charge that baptism confers or conveys saving benefits?Throughout the Leithart trial, the defense insisted, repeatedly that their ascription of effectual power to baptism stems from a straightforward reading of texts like 1 Peter 3:21 and Titus 3:5. As sort of a counterpoint to this notion, I wanted to share an extended quote from John Fesko's wonderful book on baptism, Word, Water, and Spirit: A Reformed Perspective on Baptism. Although Fesko does not deal with Federal Vision or with TE Leithart's sacramental views, he does deal with texts which seem to attribute saving power to signs, and therefore I find what he has to say very helpful.
Dr. John Collins: Right. Well then - - then it becomes incumbent upon us to ask, well what do we mean by saving and saving benefits. After all it is a Bible writer who said in Peter 3:21 baptism now saves you. And so it’s our job to understand what, what Peter means by saying that.
Leithart Trial Transcript, pg. 308
At the end of this same chapter, Fesko sums up the Reformed understanding of baptism as a sacrament:
Sometimes biblical language appears to equate the sign and the thing signified. For example, Christ gave the cup of the supper to His disciples and said, "This is My blood" (Matt. 26:28). Similarly, some interpreters see the identification of the sign and thing signified in Paul's statement to Titus: "Not by works of righteousness which we have done, but according to His mercy He saved us, through the washing of regeneration and renewing of the Holy Spirit" (3:5). And the apostle Peter says, "There is also an antitype which now saves us - baptism" (1 Peter 3:21a).
In one sense, this language is not new; there is a similar pattern in the Old Testament, where sacrificial rites were said to bring forgiveness of sins. For example, on the Day of Atonement, the animal sacrifices were an atonement for sin (Lev. 16:34). But in the New Testament, there is the seemingly contradictory statement: "For it is not possible that the blood of bulls and goats could take away sins." (Heb. 10:4). This is not doublespeak, but is what exegetes have defined as a metonymy. A metonymy is "the use of one word (often an attribute) for another that it suggests, as the effect for the cause, the cause for the effect, the sign for the thing signified." An example of a metonymy is Psalm 23:5a: "You prepare a table before me." Here the word table is a metonym for food. In this respect, biblical signs have never been an end unto themselves, but have always pointed beyond themselves to the thing signified. Thus, the Old Testament sacraments, such as the sacrifices, had no saving efficacy but pointed to the person and work of Christ, the true sacrifice that brings the forgiveness of sins through faith by the working of the Holy Spirit. The sacraments of the New Testament function in the same manner. As argued in Part II, the water of baptism points to Christ's baptism of the church with the Spirit. Therefore, Christ through the Spirit saves, not the water. This conclusion is evident in the latter half of 1 Peter 3:21: "There is also an antitype which now saves us - baptism (not the removal of the filth of the flesh, but the answer of a good conscience toward God), through the resurrection of Jesus Christ." The "answer of a good conscience toward God" is a God-given faith in the resurrected Christ. Calvin explains: "Neither ought our confidence to inhere in the sacraments, nor the glory of God be transferred to them. Rather, laying aside all things, both our faith and our confession ought to rise up to him who is the author of the sacraments and of all things" (Institutes 4.14.12).
The covenantal context of the sacraments dictates that they are not merely human pledges or oaths. The sacraments do not bring regeneration automatically to the recipient. They do not convey infused grace or habits. Neither Christ nor His church is a sacrament. The sacraments are signs and seals of the covenant of grace that points to Christ and the Holy Spirit and their respective works. They do not work faith, but instead reinforce it, as a wedding ring reinforces love (Bavinck 4.489). They are visible words that function in the same manner as the invisible words of God. Just as the Word of God is double-edged, so too are the sacraments - they hold out covenant blessing and sanction. The difference between the reception of blessing or sanction depends on the presence or absence of faith in the recipient.
Fesko, pg. 304-307