To be deep in history...

"To be deep in history is to cease to be Protestant."
--John Cardinal Newman, convert

"The Church is called Catholic then, because it extends over the whole world, from end to end of the earth; and because it teaches universally and infallibly each and every doctrine which must come to the knowledge of men, concerning things visible and invisible, heavenly and earthly; and because it brings every race of men into subjection of godliness, governors and governed, learned and unlearned; and because it universally treats and heals every class of sins, those committed with the soul and those with the body; and it possesses within itself every conceivable form of virtue, in deeds and in words, and in the spiritual gifts of every description; and if you ever are visiting cities, do not inquire simply where the House of the Lord is--for the others, sects of the impious, attempt to call their dens the Houses of the Lord,--nor ask merely where the Church is, but where is the Catholic Church. For this is the name peculiar to this holy Church, the Mother of us all, which is the Spouse of our Lord Jesus Christ, the only-begotten Son of God."--St. Cyril of Jerusalem, [ca. A. D. 350]; Catechetical Lectures, The Faith of the Early Fathers Vol. 1, William A. Jurgens (1970).

"You shall indeed hear but never understand,
and you shall indeed see but never perceive.
For this people's heart has grown dull,
and their ears are heavy of hearing,
and their eyes they have closed,
lest they should perceive with their eyes,
and hear with their ears,
and understand with their heart,
and turn for me to heal them."
--Matthew, 13:14-15