As a Sacrament, it "speaks" or "witnesses" God's Word to his people; it is a "sensible" (sensory) word or sign. In conjunction with the Spirit's work of application, it brings about just what the Word always brings about, namely faith and salvation by that instrument. The Word or Sacrament is effectual in the sovereign timing of, and according to the measure of, the power of God. That is to say, the effect is person-specific.
Thank you. I always find your comments on baptism helpful. One motivation for this thread is that occasionally, short discussions on baptism happen between my roommates and me. One is a Calvinistic Baptist who wants to develop his understanding of baptism in the history of Reformed thought; the other is a Baptist considering Reformed soteriology but not sure. They would probably want me to unpack the bold statement if I said something similar. I believe I have a good understanding of baptism in my head, but I am not great at explaining baptism in words (suggesting, no doubt, that my own understanding could stand to be improved, since I learn by teaching--I'm a "lecture to the wall" sort of learner). How would you explain what you mean by the bold statement?
We Presbyterians confess the sacraments as "means of grace." As one old Presbyterian minister from long ago put it, "You don't get a different Christ in the Sacrament [speaking of the Lord's Supper, BGB], than you get in the Word; but sometimes you get him
better." I would put the same sentiment for baptism just as truly: you don't receive a different gospel from the sacrament of baptism as you receive in the preached Word; but sometimes you receive it better.
The gospel applied by the Spirit brings faith to life in a once dead heart, which faith is made the instrument of salvation to everyone who believes. Not everyone to whom the gospel comes believes it, but in that case the problem isn't in the gospel (or its manner of expression) nor in the power of the Spirit.
It isn't my place to work-out exactly what about the love of God in Christ Jesus is communicated by the touch of water to the body; it's enough to know that God has promised to reveal himself just so. We confess something similar about the Lord's Supper. I don't know exactly how Christ communicates his body and blood to me in the Supper (his real, spiritual presence); or exactly how that meal nourishes me in faith; and yet it does according to the Word. But neither do I understand all the science behind gastronomy. I am certain that in the Sacraments we do not commune with Christ wholly by "intellectualism." Do I commune with my wife purely by ratiocination? I do not think Peter only meant the logical MIND and propositional truth, when he spoke to us about living with our wives "with understanding."
The Roman-type view sees a sacrament (baptism in this case) efficacious simply by its administration,
ex opere operato and in the event, granting the blessing (substantive grace) to the recipient.
The Lutheran-type view sees a sacrament (baptism in this case) efficacious because the Spirit and the Word of institution create faith in the recipient in the event, even in an infant, when he receives the blessing. Lutherans also confess that a saving connection can be really enjoyed
and really lost.
The Reformed view sees a sacrament (baptism in this case) efficacious by the Spirit, to whomever his sovereign dispensation wills (elect), and whenever (not necessarily tied to the moment of administration), he creates faith in that which is promised by God by the sacramental-word. Faith in that word may follow or precede the rite where it is signed/uttered. But the promise is the promise.
In the case of the infant, God makes a promise (the first word) which is believed, eventually, and confessed (the second word, the word of reply). In the case of adults, faith first makes its confession (which is actually a reply to the verbal Word), which is followed by that same Word, repeated, in the sacrament (in which we are passive recipients). God's Word always takes priority, and our words of confession are always replies. Baptism is not essentially a proclamation of my subjective faith, but a gospel proclamation of THE objective Faith.
As to whether God could begin to germinate an infant's faith in the moment of its natal baptism--obviously he can, since Scripture bears witness to such. Whether he does or not is not in that hour isn't especially concerning to us, even if the child is one of his elect. We all know of late-believers who, though they were baptized early and further discipled as youth, had hard hearts and made no pretensions to faith until many years afterward. The message of the gospel only began noticeably to affect them when (for instance) they resumed attending church for some reason. The important fact is that the gospel is proclaimed (began to be proclaimed) to an individual at almost his first Lord's Day.
On the other hand, we ought to expect discipleship (that begins at baptism) to result in a faith that is deeply rooted and persevering, when parents and the church prosecute their duties in humble obedience to God's commands from the start. We may not claim an infallible right to have an elect child; nor should we presume on the promise while ignoring the means to the end. But to think that our children's expression of faith (or lack thereof) is simply a roll-of-the-dice, no matter how we labor, is something very near unbelief in my book.
Baptism was for me the beginning of my discipling under the gospel, which has so far shown a dividend.