It is not the being seen of men that is wrong, but doing these things for the purpose of being seen of men. The problem with the hypocrite is his motivation. He does not want to be holy; he only wants to seem to be holy. He is more concerned with his reputation for righteousness than about actually becoming righteous. The approbation of men matters more to him than the approval of God.
It was not the visible sun, but its invisible Creator who consecrated this day for us, when the Virgin Mother, fertile of womb and integral in her virginity, brought him forth, made visible for us, by whom, when he was invisible, she too was created. A Virgin conceiving, a Virgin bearing, a Virgin pregnant, a Virgin bringing forth, a Virgin perpetual. Why do you wonder at this, O man?
Though there are very many nations all over the earth, ...there are no more than two kinds of human society, which we may justly call two cities, ...one consisting of those who live according to man, the other of those who live according to God ....To the City of Man belong the enemies of God, ...so inflamed with hatred against the City of God.
Whoever, therefore, thinks that he understands the divine scriptures or any part of them so that it does not build on the double love of God and of our neighbor does not understand it at all. Thus a man supported by faith, hope, and charity, with an unshaken hold upon them does not need the scriptures. . . And many live by these three things in solitude without books.
Baptism does not profit a man outside unity with the Church ... For many heretics also possess this Sacrament but not the fruits of salvation ... The benefits which flow from Baptism are necessarily fruits which belong to the true Church alone. Children Baptized in other communions cease to be members of the Church when, after reaching the age of reason, they make formal profession of heresy, as, for example, by receiving communion in a non-Catholic Church.