Exactly when infant baptism started is a matter of heated debate, but it is mentioned in early church writings as early as the second century.  There are clear lines drawn between the different Christian denominations. The vast majority, however, approximately 80%, does practice infant baptism in one form or another.  Many cite the statement in the book of Acts which states that "he and his whole house was baptized. Within the Catholic and Anglican churches, for example, an infant is "Christened" and the term baptized is reserved for adults. The primary difference, and this is even a point of contention, is that baptism involves submersion in water and Christening involves either sprinkling water on the infant or the person performing the ceremony uses fingers wetted in blessed water to make the sign of the cross on the child's forehead.  However, within this broad group of Christian denominations there are instances of either pouring water over the head of an infant or even submersion in water.  Alphabetically, the denominations which practice infant baptism or Christening in one form or another include:  Anglican (which includes Episcopal), Catholic (Roman), Eastern Orthodox, Lutheran, Methodist (including Wesleyan), Presbyterian, and United Church of Christ (including Evangelicals, Reformed Churches, and Congregational Christians).  

Denominations such as the Church of Christ or the Church of God do not practice or approve of infant baptism in any form. 

The division for the most part is a theological view or doctrine that involves a few basic questions. 

1.  Are infants born with sin, sin that is the original sin that cursed all of humanity in the garden of Eden?

2. Is baptism tied to repentance?  That is, is one required to be cognoscente of personal sin and therefore capable of repenting of sin? 

3. Can an infant accept the grace of God?

These and numerous other doctrinal or theological questions have been debated for centuries and the debate, at least for some denominations, is not over.