7 But we seek our own sign of His coming; we Churchmen seek a sign proper to the Church. And the Saviour says, And then shall many be offended, and shall betray one another, and shall hate one another. If you hear that bishops advance against bishops, and clergy against clergy, and laity against laity even unto blood, be not troubled; for it has been written before. Heed not the things now happening, but the things which are written; and even though I who teach you perish, you shall not also perish with me; nay, even a hearer may become better than his teacher, and he who came last may be first, since even those about the eleventh hour the Master receives.
If among Apostles there was found treason, do you wonder that hatred of brethren is found among bishops? But the sign concerns not only rulers, but the people also; for He says, And because iniquity shall abound, the love of the many shall wax cold. Will any then among those present boast that he entertains friendship unfeigned towards his neighbour? Do not the lips often kiss, and the countenance smile, and the eyes brighten forsooth, while the heart is planning guile, and the man is plotting mischief with words of peace?
Source: Catechetical Lectures (New Advent)