Whom God says it is limited to. The saved from the Old Testament had only the promise of a Redeemer.
Infants can have faith: Matt 18:6.
Infants can belong to the kingdom of God: Psalm 8:2 Psalm 22:9
The call to baptize is universal and never circumscribed by age, race or gender.
Infants can die demonstrating that they are not immune from the curse of original sin. In short, Baptism is God's work, not man's. God does the creation of faith, the forgiveness of sins and the spiritual regeneration that occurs at Baptism.
Learn the difference between infants and children before you go off showing how much you don’t know about Scripture.