The 15 Marks of the Catholic Church

(1) The Church’s Name, Catholic, universal, and world wide, and not confined to any particular nation or people.

(2) Antiquity, in tracing her ancestry directly to Jesus Christ.

(3) Constant Duration, in lasting substantially unchanged for so many centuries.

(4) Extensiveness, in the number of her loyal members.

(5) Episcopal Succession, of her Bishops from the first Apostles at the Last Supper to the present hierarchy.

(6) Doctrinal Agreement, of her doctrine with the teaching of the ancient Church.

(7) Union, of her members among themselves, and with their visible head, the Roman Pontiff.

(8) Holiness, of doctrine in reflecting the sanctity of GOD.

(9) Efficacy, of doctrine in its power to sanctify believers, and inspire them to great moral achievement.

(10) Holiness of Life, of the Church’s representative writers and defenders.

(11) The glory of Miracles, worked in the Church and under the Church’s auspices.

(12) The gift of Prophecy found among the Church’s saints and spokesmen.

(13) The Opposition that the Church arouses among those who attack her on the very grounds that Christ was opposed by His enemies.

(14) The Unhappy End, of those who fight against her.

(15) The Temporal Peace and Earthly Happiness of those who live by the Church’s teaching and defend her interests.
— Saint Robert Bellermine  (1542-1621)