Then little children were brought to Jesus for him to place his hands on them and pray for them. But the disciples rebuked those who brought them. Jesus said, "Let the little children come to me, and do not hinder them, for the kingdom of heaven belongs to such as these."
(Matthew 19:13-14)
Infant baptism has been the normal practice of Christians throughout the entirety of the Christian era, from the early church up to the present time. It is still the practice today among Eastern Orthodox, Roman Catholics, and most Protestant denominations. It was never a controversial or debated issue until about 1525, when those in the "Anabaptist" movement rejected infant baptism and began re-baptizing each other, viewing their infant baptisms as invalid.
(It is interesting to note that there is a political twist to the story: infant baptism was used by the secular government for tax registration, so this may have been a tax protest in disguise! If Christians had not allowed Caesar to meddle in the affairs of the church, perhaps we would not have the controversy over infant baptism today.)
One of the arguments used against infant baptism is that it is not referred to in Scripture -- that is true. But there is also no mention in Scripture of the practice of Christian parents waiting to baptize their children until they are older.
Although infant baptism is not mentioned explicitly in Scripture, there are hints of it in several passages that record the baptism of a whole "household," which may have included children and infants:
"... she [Lydia] and the members of her household were baptized..."
(Acts 16:15)
"... immediately he [the jailer] and all his family were baptized."
(Acts 16:33)
"... I [the apostle Paul] also baptized the household of Stephanas..."
(I Corinthians 1:16)
Peter replied, "Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of your sins. And you will receive the gift of the Holy Spirit. The promise is for you and your children..." (Acts 2:38-39)
The earliest explicit reference to child or infant baptism is in the Apostolic Tradition of Hippolytus, about 215 A.D.:
"Baptize first the children, and if they can speak for themselves let them do so. Otherwise, let their parents or other relatives speak for them." (Hippolytus, Apostolic Tradition 21:15, c. 215 A.D.)
Martin Luther and John Calvin, the two primary founders of the Protestant Reformation, both believed in infant baptism:
Of the baptism of children we hold that children ought to be baptized. For they belong to the promised redemption made through Christ, and the Church should administer it to them. (Martin Luther, The Smalcald Articles, Article V: Of Baptism, 1537)
"If, by baptism, Christ intends to attest the ablution by which he cleanses his Church, it would seem not equitable to deny this attestation to infants, who are justly deemed part of the Church, seeing they are called heirs of the heavenly kingdom." (John Calvin, Institutes of the Christian Religion, 1559)
Nevertheles, there are a minority of Protestants who do not practice infant baptism but who wait until children have reached an "age of accountability" (also not referred to in Scripture) to be baptized.
In his article What About Infant Baptism? Mark Copeland presents some common Protestant arguments against the historic Christian practice. The author makes two major points: (1) Infant baptism is not "real" baptism, because it is not immersion. This is erroneous, because all persons baptized in the Orthodox Church, whether as infants or as adults, are baptized by full immersion. When our son Garrett is baptized, he will be immersed in water not just once, but three times, in the name of the Holy Trinity. (2) Babies "are not lost and in need of salvation." Copeland interprets the doctrine of "original sin" to mean that babies are born with the guilt of Adam's sin, and he rejects the doctrine on that basis. This, however, is a misunderstanding of original sin. What we inherit from Adam is not personal guilt but a fallen nature that is subject to death. "God created man for incorruption" (Wisdom of Solomon 2:23), but "sin entered the world through one man, and death through sin, and in this way death came to all men" (Romans 5:12). Thus, the author's case against infant baptism is based on two errors -- a factual error and a theological error.
Orthodox Christians understand baptism to be a sacrament or a mystery -- a visible means by which the grace of God is communicated to us.
We understand the sacraments of the New Covenant, established by Christ in the church, to be the fulfillment of the types and images that were foreshadowed in the Old Covenant, between God and the people of Israel. (See Hebrews 9-10) In the Old Testament, circumcision was the means by which a Jew entered into the covenant of Abraham. In the New Testament, it is baptism which marks our entrance into the kingdom of God, the beginning of our Christian life. Just as Jewish boys were circumcised as infants, so also the children of Christian parents are baptized as infants. St. Paul makes this explicit link between circumcision and baptism:
In [Christ] you were also circumcised, in the putting off of the sinful nature, not with a circumcision done by the hands of men but with the circumcision done by Christ, having been buried with him in baptism and raised with him through your faith in the power of God, who raised him from the dead. (Colossians 2:11-12)
When does a person's Christian life begin? For an adult, it begins at the time that one freely chooses to embrace the apostolic faith in Christ. But for a child born into a Christian home, the Christian life begins at birth, as his parents teach him to love God, as they read the Scriptures to him and teach him to pray with them, and as they bring him to church regularly to worship with other believers.
While baptism marks the beginning of our Christian life, each of us who are baptized must continue daily to persevere in our faith until the end of our earthly life. As St. Paul says:
"Not that I have already obtained all this, or have already been made perfect... I do not consider myself yet to have taken hold of it. But one thing I do... I press on toward the goal to win the prize..." (Philippians 3:12-14)
One final point that bears mention: the Orthodox Church practices not only infant baptism but also infant communion. In the Catholic Church, children are baptized as infants but do not receive the Eucharist until they are old enough (typically around 7-8 years old) to make their first confession of sins and then receive their "First Communion." Then, at an older age (usually 12-15 years), they receive the sacrament of confirmation (called chrismation in the Orthodox Church). By contrast, in the Orthodox Church, the three sacraments of initiation -- baptism, chrismation and the Eucharist -- are all administered to babies, and children continue to receive communion regularly throughout infancy and childhood.