Dear friend in Christ, infant baptism dates back to the earliest centuries of the church, as corroborated by the Early Church Fathers.
"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."
St. Hippolytus of Rome ("The Apostolic Tradition," 215 A.D.)
Infant Baptism is biblical. In Acts 10:47-48, we read that Peter baptized the entire house of Cornelius, which generally included infants and young children. There is not one word in Scripture about baptism being limited to adults. In Acts 16:15, Paul baptized Lydia and her entire household. The word "household" comes from the Greek word "oikos" which is a household that includes infants and children. Paul baptizes the household based on Lydia's faith, not the faith of the members of the household. This demonstrates that parents can present their children for baptism based on the parents' faith, not the children's faith.
I will credit the Roman Catholic Church with its practice of Confirmation. However it is the entire process of conversion, beginning with adult baptism and culminating in mature confirmation that is sacramentally effective. Being raised in the Roman Catholic Church, I believe that being confirmed at 11 years old was not what I consider a mature confirmation. I believe the Church puts it members through such a sacrament at too young of a age. By doing so, the person misses the real benefit one would get through their maturity. It is like the Church is so hung up on their theology that they fail to make their theology effective for the believer. And by doing so, many of their believers are falling into the moral quagmire because of their weak faith.