Some might say … based on his defense of infant baptism, that Luther didn’t really believe in the gospel.
In a previous post where I summarized Luther’s doctrine of baptism, I gave a summary of each of his arguments for infant baptism as presented in the Large Catechism. This post will take a close look at Luther’s logic for defending infant baptism. If you have not been following the post series so far, it is important to at least realize this: Luther was a virtual Roman Catholic when it comes to the saving efficacy of the sacraments. Luther did not believe in the same sola fide that D.A. Carson, R.C. Sproul, and many other modern Reformed evangelicals consider to be fundamental to the gospel. By R.C. Sproul’s standards, Luther should be considered a non-Christian for not believing in his version of sola fide. This is an inconvenient truth, for Sproul and many others with his position actually believe they are the modern champions of Luther’s doctrine of justification. But get this: Luther assumes that baptism saves, period. As we have seen, he attempts to avoid the accusation of believing in salvation by works by retorting that Baptism is the work of God, and therefore not salvation by works (so argues Luther). Now we will critique his attempt to establish the validity of infant baptism. This post will be especially pertinent for baptists.
Luther’s Defense of Infant Baptism as Involving Logical Fallacies
The Historical Fallacy
Luther’s first argument for infant baptism (based on the fact that infants who are baptized later demonstrate the fruits of the Spirit) commits the historical fallacy known as post hoc, propter hoc (“the mistaken idea that if event B happened after event A, it happened because of event A,”). His proposal begs an important question: Are the fruits of the Spirit caused by their baptism? Luther assumes his doctrine of baptismal regeneration to prove his doctrine of infant baptism, but the former, as we have noted, has not been demonstrated on sound principles of interpretation. His logic could be summarized like this: Since the only way you can possibly receive the Holy Spirit is through baptism (Luther’s assumption), if an infant who is baptized is later shown to bear the fruits of the Spirit, we can safely conclude that their baptism “worked,” and that God blesses infant baptism according to the promise. Luther assumes the very causal relationship between baptism and salvation which his critics would not be willing to grant. Surely those critics who opposed Luther on infant baptism were not ready to concede that God saved infants through baptism. Here we see the very same assumption we have previously observed Luther take for granted in his other arguments against those who deny baptismal regeneration.
The second argument Luther makes in favor of infant baptism begs the same causal relationship as his first argument. Luther basically applies the same logic to particular people, namely, the entire history of the church—particularly the early church fathers. They were baptized in infancy, and we know that God gave them His Holy Spirit. Therefore, Luther concludes that God has endorsed infant baptism in church history. His further argument is that God would be in conflict with himself if he were giving the Holy Spirit to people who were baptized as infants if indeed the practice displeased Him. With this line of argument, Luther continues to assume the causal relationship between infant baptism and the salvation of the church. I might use this same logic to prove that God obviously blesses sin, since all Christians have sinned by practicing infant baptism and yet God has given them the Holy Spirit. It may have been (and indeed, I would argue was) in spite of their practice of infant baptism that God gave these men the Holy Spirit. Furthermore, how would Luther ever be able to demonstrate that anyone who bore the fruits of the Spirit after infancy received the Holy Spirit at their baptism and not some time after their baptism? Luther seems to be wholly unaware that his arguments will only work for those who share his assumptions about the sacramental limitation of saving grace in baptism.
Begging the Question
When Luther starts arguing that baptism is valid whether or not faith is present in the one being baptized, it is more difficult to follow his reasoning but easy to see that it is flawed. When Luther declares that a lack of faith does not “invalidate” baptism because “when the Word accompanies the water, Baptism is valid,” he is continuing to beg the same question he has been begging in every argument we have examined so far. His further argument that “Baptism does not become invalid even if it is wrongly received or used, for it is bound not to our faith but to the Word,” simply means this: Since God promised to save through baptism without exception, we must assume he saves through baptism without exception. Again, this begs the important question. That “we know that God does not lie,” is not enough to prove his case, for only if we assume God promised salvation through baptism could we consider God a liar if baptism did not save an infant.
Ambiguity and Equivocation
However, when Luther expands on this idea through illustration, his argument is further complicated by ambiguity. First, Luther does not make clear whether he is speaking of “validity” from the vantage point of the one who administers the baptism, or from the vantage point of those who receive the baptism. The illustration of the deceitful Jew who tricks a minister into baptizing him fails to draw the distinction between validity from the vantage point of the dishonest Jew and validity from the vantage point of the administer of his baptism. The latter would be blameless in the matter. As far as the rules by which the sacraments are supposed to be administered, he has administered validly. However, the deceitful Jew has not experienced a valid baptism, because he was not only being baptized for the wrong motives, but without any faith in Christ whatsoever.
The major problem with Luther’s argument for the “validity” of baptism without faith, therefore, could be described as either ambiguity or as committing the fallacy of equivocation (equivocating the on the term “validity”). Luther’s illustration is supposed to ground his argument that the sacrament is valid without distinction, but his illustration only proves that baptism can still be administered validly even when it is not received validly. Because of this, his claim that infant baptism is valid, is either too ambiguous to be proven, or if we assume he means “valid” in an unqualified sense, his illustrations do not help to prove the kind of validity necessary to make a case against his opponents.
Fallacy of False Analogy
There is another flaw with the illustrative part of Luther’s defense. Proving that the baptism can be validly administered to an adult who claims to have faith in Christ but does not (the Jew in Luther’s illustration), is incapable of proving the validity of administering baptism to an adult who does not claim to have faith, much less an infant who cannot even claim to have faith. If Luther’s illustration cannot prove his claim that baptism should be administered whether or not the recipient has faith, much less is it able to prove the validity of infant baptism. His argument simply has no particular relevance to infant baptism, in which case the infant is not even claiming to have faith. Yet this is what Luther is supposed to be proving—that infant baptism is valid because baptism in general remains valid even when “wrongly received or used.” There is not enough legitimate parallel in Luther’s illustration to carry any weight towards defending infant baptism.
When Luther attempts to compare the Anabaptist position (that baptism is only valid if faith is present in the recipient) to the position that Christ is only Lord when people believe him to be so, he argues against a straw man. The differences between these two positions should be painfully obvious, and they consequently nullify Luther’s argument. Luther’s argument assumes that if his opponents hold that the recipient of baptism must have faith in order for baptism to be valid, we must also grant that things other than baptism are only valid or genuine if someone has faith in them. Luther is embarrassingly sloppy at this point. To say that faith is a necessary ingredient for a baptism to be valid (from the perspective of the recipient) is very different than holding that faith is a necessary ingredient for anything to be genuine or valid. Luther, therefore, although claiming simply to press the logic of his opponents to its absurd conclusion, is in fact pressing the position of his opponents beyond what their position logically demands. Thus, Luther is guilty of caricaturizing his opponent’s position. We might return the fallacy by using the same logic against Luther, and so argue that his position (that baptism is valid even without faith) requires him to hold that the whole Christian life might be lived validly apart from any true faith.
Incoherency Within Luther’s Own Position
An important point to notice about Luther’s defense of infant baptism is the tension which results from his separation of faith from the moment baptism is administered. On the one hand Luther holds that baptism is not efficacious unless it is “received by faith,” but on the other hand he holds infant baptism to be “valid” even when the infant does not have faith before, during, or years after the baptism. The necessary inference which must be drawn, then, is that baptism is not always immediately efficacious. Although, as we have already seen, Luther admonishes his readers to believe (“if you did not believe before [when you were baptized], then believe afterward and confess”), this does not resolve the tension between his holding to the efficacy of baptism on the one hand, and delayed effects of baptism on the other. We might call this doctrine delayed efficacy, and it is a definite tension which goes unresolved in The Large Catechism. If Luther holds out this possibility—that faith need not be present at the moment of baptism or even years after—then Luther would be wrong to say that baptism is efficacious in the normal sense of sacramental efficacy. It would have been more logically clean for Luther to hold that infants receive faith through the baptism rather than holding out the possibility of infant baptism with a delayed efficacy.
Another tension which is never resolved in Luther’s framework involves his warning about separating faith from baptism. First of all, Luther himself is guilty of separating faith from baptism with his doctrine of delayed efficacy. Secondly, his admonishment to others not to separate the two is out of place in his paradigm. This second problem follows from the fact that real faith cannot exist apart from the regenerative work of the Holy Spirit, who, in Luther’s paradigm, is received only through baptism. In other words, if faith is a gift of the Holy Spirit, and the Holy Spirit is not received until baptism, then it does not make sense to admonish anyone to “receive” their baptism in faith. It would make more sense to admonish them to receive their faith in faith, but this does not comport well logically either.
Furthermore, if faith must come through baptism (unless God is a liar who promised the Holy Spirit in baptism, with all his gifts)—that is, if faith cannot not be a result of baptism—what need is there to warn people not to separate faith from baptism? Given Luther’s paradigm, there is no possible danger of separating faith from baptism, because faith is effectively produced in baptism by God himself. Yet Luther insists on not administering baptism when faith is not present: “Baptism helps no one and is to be administered to no one unless he believes for himself. No one who does not personally believe is to be baptized.” Luther’s admonishments not to separate faith from baptism, then, are not fitting for two reasons: 1) He himself temporally separates the two from one another in infant baptism and 2) his view of efficacy makes such a separation impossible. For these reasons, it is a logical headache to follow Luther in his incoherent attempt to justify infant baptism apart from faith.
 Luther was forced to use logic, because he admitted that there were no direct commands in the New Testament to baptize infants. He thought that since the great commission was a simple command to baptize without any mention of faith as a condition, infant baptism was implicated in the command. Lohse, Martin Luther’s Theology, 303. Althaus, The Theology of Martin Luther, 361.
 Carson, Exegetical Fallacies, 133.
 Karl Barth believed that “Luther’s defense of infant baptism is sustainable once the presuppositions of his wider theology of baptism are admitted.” Trigg, Baptism in the Theology of Martin Luther, 4. This is precisely because Luther’s defense everywhere assumes his paradigm and begs the key questions.
 It seems that Lohse misses this crucial part of Luther’s argument at this point. Lohse summarizes this argument like this: “God would not have allowed something improper to be in force for so long.” Lohse, Martin Luther’s Theology, 303. However, Luther’s argument was not simply that infant baptism had always been practiced, but that unless God was giving his Holy Spirit through those baptisms, there would be no church. “…in short, all this time down to the present day no man on earth could have been a Christian.” Luther, The Book of Concord, 441. If baptism is the only way God gives his Holy Spirit, and the church members were all baptized in infancy not as adults—the Holy Sprit had to have been given through their baptism or else there would be no church. Althaus first gives a similar summarization as Lohse, but sees Luther as giving two arguments instead of one. The second argument he summarizes like this: “It also must be said that if infant baptism were false and contrary to God’s will, then there would have been no true baptism and thus also no church for more than a thousand years. For without baptism there is no church.” Althaus, The Theology of Martin Luther, 360. Luther, however, never voices any such argument in the Catechism, but only speaks in terms of the Holy Spirit’s being present in the church. Perhaps Althaus is aware of a passage that would shed more light on what Luther meant in the Large Catechism. Otherwise it seems to be reading into the Luther’s argument.
 Lohse rightly recognizes that Luther appealed to “the concept of the sacrament as ‘effective in itself’ (ex opere operato)” in his defense of infant baptism. Lohse, Martin Luther’s Theology, 302.
 Luther, The Book of Concord, 444.
 Ibid., 443.
 Ibid., 443.
 “Yet even if they could establish that children are without faith when they are baptized it would make no difference to me … for faith doesn’t exist for the sake of baptism, but baptism for the sake of faith.” Martin Luther, Luther’s Works, vol 40, Church and Ministry II, 240-41.
 Althaus quoting Luther, The Theology of Martin Luther, 364.
 Althaus says in regard to the problem of making faith necessary and still seeing infant baptism as valid, “Luther’s thoughts about this are not always constant but are in a process of development.” Ibid., 364.