Here is yet another quote from the great St. Augustine in support of Extra Ecclesiam taken from his work Admonition and Grace (Fathers of Church, Cath. Univ., vol. 4):
"Moreover, I shall not delay over the baptism of infants (which as our adversaries must admit, certainly belong to the kingdom of God, even if the above mentioned things do not), nor consider why it is given to one and not to another, when to give it or not to give it is equally in the power of God, and without that sacrament no one enters the kingdom of God." (p. 267)