Imitation of Christ

Cum mane fuerit, puta te ad vesperum non perventurum. Vespere autem facto, mane non audeas tibi polliceri. Semper ergo paratus esto, et taliter vive, ut nunquam imparatum te mors inveniant. Multi subito improvisi moriuntur. Nam hora, qua non putatur, Filius hominis veniet. Quando hora illa extrema venerit, multum aliter sentire incipies de tota vita tua præterita et valde dolebis, quia tam negligens, et remissus fuisti.

When it is morning reflect that it may be that you will not see the evening, and at eventide dare not to boast of the morrow. Always be prepared, and so live that death may never find you unprepared. Many die suddenly and unexpectedly. For at such an hour as you do not plan, the Son of Man comes. When that last hour shall come, you wilt begin to think very differently of your whole life past, and will mourn bitterly that you hast been so negligent and slothful.

Imitation of Christ, I, 23:3