There is a Catholic whom I talk to and he told me that the reason for baptizing infants is for the opportunity for them to put on the body of Christ if they were to pass away before reaching the age of accountability. They also say that Paul went into the households and baptized the household and households include infants. Now Scripture does not specify who was in the homes;yet, the Scripture specifies what is needed to take place in order to be baptized, which an infant can't do (believe and repent). They also believe we inherit Adam's sin when we are born. They call it "original sin," so getting baptized as an infant washes away the original sin. I asked them where an infant is going if an infant dies and his parents did not baptize him in time? Their answer was they are not in the place to state where and it's only in God's hands, even though they know children are innocent.
I read many of your articles behind infant baptism and of course I do understand why it's not needed and was never done. But my question is: what is the reasoning behind infant baptism to which the Catholic stand on it so strongly since it's not in Scripture? They bring up many of the Apocrypha and pseudo books and claim other writings from the Apostles' disciples.
Historically, infant baptism began before the teaching of original sin. The earliest mention of infant baptism is by Irenaeus in c. AD 180: "For he came to save all through means of Himself – all, I say, who through Him are born again to God – infants and children, and boys, and youths, and old men." [Against Heresies, vol. 1, p. 391]. Origen (185-c. 254) also mentioned the practice: "Baptism according to the practice of the church is given even to infants." I suspect the initial impulse was to imitate the Jews and have a ritual that would keep children in the church as they grew up.
Later justification was sought for a practice already being done. "Ecclesiastical custom with regard to the administration of Baptism has undergone a change in the course of history. Whereas the early Church baptized adults only, the baptism of children soon became the usual practice." [Pastoral Medicine, pages 32-33].
The teaching of original sin can be traced back to Augustine. He based his teachings on something Origen said, "Infants are baptized for the remission of sins ... that is the reason infants are baptized." Augustine argued that this sin must have been inherited since the child would have no opportunity to sin on his own. It was Augustine who also argued that unbaptized infants would end up in hell. With this claim, infant baptism spread widely. "Where in the fourth and fifth centuries the doctrine of original sin became better known, the practice of infant baptism progressed rapidly." [Legislation on the Sacraments in the New Code of Canon Law, page 72].
By the Middle Ages a doctrine was developed to soften Augustine's claim that unbaptized infants went to hell. The new doctrine was that unbaptized infants went to Limbo -- a place that was neither heaven or hell. In 1992 "limbo" was removed from the Catholic Catechism and in 2007 a document was issued that lowered limbo from a required belief to a "theological hypothesis."
Oddly, even Catholic doctrine openly admits that there is no foundation for the practice of infant baptism. It is done without any absolute evidence.
"When the New Testament mentions the practice of Baptism, it generally points to the Baptism of adults. But the New Testament evidence does not preclude the possibility of infants being baptised. In households (oikos) where Baptism is mentioned in the Book of Acts 16:15 and 33 (cf. 18:8) and 1 Cor 1:16, children may have been baptised along with adults. The absence of positive evidence may be explained by the fact that the New Testament writings are concerned mainly with the initial spread of Christianity in the world." ["The Hope of Salvation for Infants Who Die Without Being Baptised", International Theological Commission].
The same document states that they are unsure if infant baptism saves or not. "The conclusion of this study is that there are theological and liturgical reasons to hope that infants who die without baptism may be saved and brought into eternal happiness, even if there is not an explicit teaching on this question found in Revelation." [ibid]. Roman Catholicism continually changes, and as a result current beliefs will often contradict old beliefs.
Another possible reason in additions to the original sin issue is because they want to claim numbers. Once you are baptized, you are a "Catholic" for life by their view. Or as the old saying goes: "once a Catholic, always a Catholic."
As for the extra biblical books they use, they have been proven without a doubt as uninspired and contradictory of God's word. But this doesn't make a Catholic flinch because the majority of their faith is not based on Scripture but on traditions. For more information on these type of books see: Apocrypha.