We might see four areas in which Augustine was dominant.
First, when he tried dividing his love between God and his mistress he gave in,
saying, "Our hearts are made for you, Oh God, and they cannot rest until they
rest in you."
Next, while Christians had been saying that any true sacrifice had to
end in the death of a victim, Augustine taught that the sacrifice of the Mass
consisted in Christ and his followers entirely submitting their selves to God.
Thirdly, a fallen away priest could seemingly enact a true Sacrament, since
every sacrament is actually conferred by Christ.
Fourth, Augustine demonstrated the truth that we cannot save ourselves, that
salvation comes only from God.