66 bishops gathered at a local Council of Carthage in 252 under the presidency of my namesake, Holy Hieromartyr Cyprian, where they decreed:
"Not to forbid (the baptism) of an infant who, scarcely born, has sinned in nothing apart from that which proceeds from the flesh of Adam. He has received the contagion of the ancient death through his very birth, and he comes, therefore, the more easily to the reception of the remission of sins in that it is not his own but the sins of another that are remitted."
This declaration is reiterated in Epistle LVIII by St. Cyprian to Fidus:
"But again, if even to the greatest sinners, and to those who had sinned much against God, when they subsequently believed, remission of sins is granted--and nobody is hindered from baptism and from grace--how much rather ought we to shrink from hindering an infant, who, being lately born, has not sinned, except in that, being born after the flesh according to Adam, he has contracted the contagion of the ancient death at its earliest birth, who approaches the more easily on this very account to the reception of the forgiveness of sins--that to him are remitted, not his own sins, but the sins of another. "
Furthermore, 217 bishops gathered at the Council of Carthage in 419 and decreed in Canon 110 of what is dubbed the "African Code":
Canon CX.
[Greek CXII]
That infants are baptized for the remission of sins.
Likewise it seemed good that whosoever denies that infants newly from their mother's wombs should be baptized, or says that baptism is for remission of sins, but that they derive from Adam no original sin, which needs to be removed by the laver of regeneration, from whence the conclusion follows, that in them the form of baptism for the remission of sins, is to be understood as false and not true, let him be anathema.
For no otherwise can be understood what the Apostle says, "By one man sin is come into the world, and death through sin, and so death passed upon all men in that all have "sinned," than the Catholic Church everywhere diffused has always understood it. For on account of this rule of faith (regulam fidei) even infants, who could have committed as yet no sin themselves, therefore are truly baptized for the remission of sins, in order that what in them is the result of generation may be cleansed by regeneration.
The African code was ratified by the Quinisext Ecumenical Council (i.e. the Council of Trullo in 692), attended by more than 200 bishops, as well as the Holy Sixth and Seventh Oecumenical Councils.
So these canons bear Ecumenical authority and cannot simply be rejected. They are not optional.
The Orthodox must accept that infants are baptized for the remission of sins, as is confessed in the Holy Symbol of Faith just prior to their entering the laver:
"I confess one baptism for the remission of sins"
To suggest that infants are baptized for a different reason than adults is to confess not one baptism -- "One Lord, one faith, one baptism" (Eph 4.5) -- but in fact to confess two baptisms.
Cyprian