Church,  Theology

Faith and Infant Baptism in Augustine and Aquinas

The historical evidence shows that infant baptism was regularly practiced from at least the 3rd or 4th century until the present day. One of the topics of discussion in the early church was how baptism could be an expression of faith when infants are not capable of expressing their own faith.

photo of saint Augustine who wrote on faith and infant baptism

Of particular importance in this discussion was Augustine, who is well known for being the most influential theological figure of that time. In Augustine’s discussion of baptism, after having explained that baptism belongs to those who repent of their sins, Augustine addresses the obvious problem of what are infants repenting?

“Now, inasmuch as infants are not held bound by any sins of their own actual life, it is the guilt of original sin which is healed in them by the grace of Him who saves them by the laver of regeneration.”[1]

In other words, although infants do not have any sins they themselves have committed, they must repent of original sin which is passed down through Adam. Obviously someone could raise the objection that it is not really repentance if infants have no ability to confess and forsake sin on their own. To this Augustine replies,

Some one will say: How then are mere infants called to repentance? How can such as they repent of anything? The answer to this is: If they must not be called penitents because they have not the sense of repenting, neither must they be called believers, because they likewise have not the sense of believing. But if they are rightly called believers, because they in a certain sense profess faith by the words of their parents, why are they not also held to be before that penitents when they are shown to renounce the devil and this world by the profession again of the same parents?[2]

Augustine’s Alien Faith

We must take careful note of Augustine’s point here. His argument presumes the necessity of belief and repentance in baptism, but since the child is incapable, Augustine argues the parent’s words of faith and penitence are attributed to the child. Theologically this phenomenon is called fides aliena, a faith of others.[3]

However, this concept of fides aliena prompted some significant debate. Although the problem of the infant having faith is resolved, a difficult question arises in its place—who is it that believes on behalf of the infant? The logical dilemma is brought forward as follows:

If fides aliena solves the problem of the infant’s lack of faith, it opens up a new question: who actually does the believing? The early scholastics reckoned with the possibility that parents or sponsors may not really believe. In this case, the act of believing devolves upon the church as a whole, as Augustine had said.[4] But what if the entire church was in error? Then, said the early scholastics, it is the faith of the ecclesia triumphans, the church already in heaven, that suffices. But the church triumphant does not need faith; how can it “believe”? Answer: its faith is on deposit in the treasury of merits. So the theologians spun out the strands that came from the Pandora’s box that Augustine had opened.[5]

The Baptism Debate

An Infused Faith

The unsatisfactory theological consequences of Augustine’s fides aliena led to the Catholic development of fides infusa baptisme, a special “virtue or power infused by baptism.”[6] Continuing with the idea that faith and baptism must be related, medieval thinkers like Peter Lombard proposed that the church conferred faith on the infant through the act of baptism.[7]

Even renown Catholic theologian, Thomas Aquinas jumped into this debate. In his Summa Theologiae, Aquinas relied on Augustine, arguing that, “So that children believe, not by their own act, but by the faith of the Church, which is applied to them: by the power of which faith, grace and virtues are bestowed on them” (Summa Theologiae, Q 69, A 6). 

Although fides infusa became a dominant view in the Catholic church, like its predecessor fides aliena it suffers from an obvious dilemma. If the New Testament teaches faith is a prerequisite for baptism, then “faith cannot be both the prerequisite for baptism and the gift bestowed by baptism.”[8]

It is not my goal in this post to evaluate the development of Catholic theology, or necessarily critique it. Rather, I want to make the simple point that from Augustine through the medieval period the unanimous opinion was that faith and baptism were somehow related. Although the exercise of volitional faith prior to baptism was easily accounted for in adult converts, the relationship of faith and infant baptism was heavily debated and led to two prevailing views—neither of which denied the relationship between faith and baptism, only tried to make sense of it. In contrast to the historical understanding of infant baptism and faith, in Reformed paedobaptist circles most proponents argue strongly that baptism has nothing to do with faith.

[1] Augustine of Hippo, “A Treatise on the Merits and Forgiveness of Sins, and on the Baptism of Infants,” in Saint Augustin: Anti-Pelagian Writings, ed. Philip Schaff, trans. Peter Holmes, vol. 5, A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, First Series (New York: Christian Literature Company, 1887), 24.

[2] Augustine of Hippo, “A Treatise on the Merits and Forgiveness of Sins, and on the Baptism of Infants,” in Saint Augustin: Anti-Pelagian Writings, ed. Philip Schaff, trans. Peter Holmes, vol. 5, A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, First Series (New York: Christian Literature Company, 1887), 24.

[3] Elsewhere Augustine notes that this principle only applies to infants. Cf. Augustine of Hippo, “On Baptism, against the Donatists,” in St. Augustin: The Writings against the Manichaeans and against the Donatists, ed. Philip Schaff, trans. J. R. King, vol. 4, A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, First Series (Buffalo, NY: Christian Literature Company, 1887), 462. “Therefore, when others take the vows for [infants], that the celebration of the sacrament may be complete in their behalf, it is unquestionably of avail for their dedication to God, because they cannot answer for themselves. But if another were to answer for one who could answer for himself, it would not be of the same avail. In accordance with which rule, we find in the gospel what strikes every one as natural when he reads it, ‘He is of age, he shall speak for himself.’”

[4] Augustine of Hippo, “A Treatise on the Merits and Forgiveness of Sins, and on the Baptism of Infants,” in Saint Augustin: Anti-Pelagian Writings, ed. Philip Schaff, trans. Peter Holmes, vol. 5, A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, First Series (New York: Christian Literature Company, 1887), 30. “And that this takes place in the case of infants, through the sacrament of baptism, is not doubted by mother Church, which uses for them the heart and mouth of a mother, that they may be imbued with the sacred mysteries, seeing that they cannot as yet with their own heart ‘believe unto righteousness,’ nor with their own mouth make ‘confession unto salvation.’

[5] Jonathan H. Rainbow, “‘Confessor Baptism’: The Baptismal Doctrine of the Early Anabaptists,” in Believer’s Baptism: Sign of the New Covenant in Christ, ed. Thomas R. Schreiner and Shawn D. Wright, NAC Studies in Bible & Theology (Nashville, TN: B & H Academic, 2006), 191.

[6] Rainbow, “‘Confessor Baptism’: The Baptismal Doctrine of the Early Anabaptists,” 191.

[7] Rainbow, “‘Confessor Baptism’: The Baptismal Doctrine of the Early Anabaptists,” 191. Rainbow cites A. M. Landgraf, Dogmengeschichte der Frühscholastik, Dritter Teil: Die Lehre von den Sakramenten (Regensburg: Verlag Friedrich Pustet, 1954), 323, as a scholar who claims fides infusa was the “distinctive contribution” of scholastic thought concerning the relationship between faith and baptism.

[8] Rainbow, “‘Confessor Baptism’: The Baptismal Doctrine of the Early Anabaptists,” 191.

Peter serves at Shepherd's Theological Seminary in Cary, NC as the professor of Old Testament and Biblical Languages. He loves studying the Bible and helping others understand it. He also runs The Bible Sojourner podcast and Youtube channel.


  • Scott Cooper

    These are excellent observations but I think Augustine’s views deserve a little more attention. There is indeed a progression or “an accumulation of teachers” evident in the history of baptismal theology and you’ve laid out key shifts in that progression very well. I’d be interested in citations to more of the primary sources. I don’t have the Rainbow text you cite.

    I don’t know when “fides aliena” is first articulated but it doesn’t appear Augustine ever used that term with regard to baptism and I don’t think it’s an accurate description of his belief. Rather, I think it derives from a misunderstanding of his belief from those that came after him (or an innovation on it). A search of the Latin Perseus Digital Library for the exact term only turns up one hit. It is Augustine but it seems to be used in a non-baptismal context.

    There are a few other factors that I think are necessary for understanding Augustine’s view, holistically. First, it’s fairly clear that John 3:5 was interpreted quite literally by most of the early church, but not in the way it’s often described today, as we have a tendency to compartmentalize ideas (especially in the Protestant West) such that we don’t see inter-relationships in them. For example, the view that baptism isn’t strictly necessary has led to an undervaluing of it’s connectedness with faith and official recognition of it as membership in the church.

    I think Augustine pretty well solidifies the idea that baptism is absolutely necessary for salvation in the West but he never seems to disassociate it from the personal faith of the individual, even for infants. That sounds odd for us but we live within a different theological, cultural, scientific, and sociological framework (e.g. with regard to human development) and these things influence our thinking and the expression of our faith, as does our response (perhaps overreaction) to the misakes of history. For Augustine and others in the early church, baptism is one side of a single, two-sided coin. In his Sermon 294.12 (usually dated to around 413), he gives us a glimpse into the litugical expression of his thought:

    “Here, you see, the answer is given by those who are carrying the babies. They are healed at someone else’s words, because they’re wounded at someone else’s deed. ‘Do they believe in Jesus Christ?’ goes the question; the answer is given, ‘They do.’ For infants who can’t speak, who remain silent, who cry, and by crying are somehow or other praying to be helped, the answer is given, and is effective.”

    I’m not sure of translational nuance (there may be significance in “at someone else’s words” vs. “by” them) but note his use of a third-person response and the implication that there is a desire “to be helped,” whether in silence or not. It appears he views the sponsor as a conduit for the expression of the infants faith, not a substitute for it. For Augustine, it is still a “believers baptism,” in a sense, the sponsor functioning as a mere informant. Everett Ferguson mentions this and cites another scholar (De Latte, “Rituel baptismal des enfants,” pg. 47) who uses this description.

    Something else notable is his comparison to being “wounded at someone else’s deed,” which is a reference to original sin. In the same sermon, he referes to original sin as “derived
    from the first parent.” That is, the guilt of original sin is an inherited stain but the newborn isn’t responsible for the actual sin committed by the “first parent.” Similarly, the infant derives necessary public witness to their belief (faith) from the sponsor but it is not the sponsors actual faith that is credited to the infant.

    As odd as these ideas sound to us today, I think it makes a lot more sense if you consider Augustine’s views on God’s sovereighnty, predestination, and election, which are well known and more easily understood. When you put it all together, I think it’s appropriate to suggest Augustine probably believed the infants being baptized were elect and predestined to experience the “baptism” side of the coin. Should they live long enough, they would certainly come to visible faith and persevere to the end.

  • Dwight Osborne

    The counterfeit Roman catholic church began the practice of infant baptism, but let’s make it ABSOLUTELT CLEAR, THE CATHOLIC CHURCH ISN’T CHRISTIAN. The vatican serves and worships as its lord and master that old dragon, satan, aka Abaddon and Apollyon. It was adopted, practiced and taught by John Calvin, but again we must be ABSOLUTELY CLEAR; JOHN CALVIN WAS NOT A BORN-AGAIN MAN. He was not a saved Christian. The Bible teaches that water baptism identifies an individual with the death, burial and resurrection of Messiah and occurs AFTER or as a result of salvation, Romans 6:3-7 God’s word goes on to say that we are saved by the baptism of the Holy Spirit, Titus 3:5, which occurs IMMEDIATELY upon the indwelling of the Ruach HaKodesh which happens at the moment one believes by faith alone in Christ alone, Galatians 3:2, Habakkuk 2:4, Romans 1:17, Galatians 3:11, Hebrews 10:38, Romans 3:30 ANYONE, regardless of who they are who says differently calls the Bible a lie, Yehovah the Father, Yeshua the Son and God the Ruach HaKodesh all liars in accordance with God’s own personal indictment in 1 John 5:10, but in reality that individual is the one who is the liar.

    • Dwight Osborne

      The Anabaptists were indeed absolutely correct and those who persecuted the Anabaptists , regardless of who they were, will pay a huge price at the great white throne judgment, or if they were actually saved, at the bema judgment after the rapture.

    • Jim Martel

      You appear to be quite judgmental in your assessment of Catholics and Calvinist. Now I’m not crazy about either one, but it isn’t necessary to make a blanket statement saying they are not Christians and call people liars, – “who says differently calls the Bible a lie.” We shouldn’t judge entire denominations or groups that DO believe in Christ life, miracles, crucifixion, resurrection, and ascension.

  • Jim Martel

    The Didache mentions baptism. It says it should take place outdoors in running or flowing water. Verse 2 tells us that if running water was unavailable, Christians were free to baptize with other water, preferably cold water. Even from a puddle!

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