1 The root of all good works is the hope of the Resurrection; for the expectation of the recompense nerves the soul to good works. For every labourer is ready to endure the toils, if he sees their reward in prospect; but when men weary themselves for nought, their heart soon sinks as well as their body. A soldier who expects a prize is ready for war, but no one is forward to die for a king who is indifferent about those who serve under him, and bestows no honours on their toils.
In like manner every soul believing in a Resurrection is naturally careful of itself; but, disbelieving it, abandons itself to perdition. He who believes that his body shall remain to rise again, is careful of his robe, and defiles it not with fornication; but he who disbelieves the Resurrection, gives himself to fornication, and misuses his own body, as though it were not his own. Faith therefore in the Resurrection of the dead, is a great commandment and doctrine of the Holy Catholic Church; great and most necessary, though gainsaid by many, yet surely warranted by the truth. Greeks contradict it, Samaritans disbelieve it, heretics mutilate it; the contradiction is manifold, but the truth is uniform.
Source: Catechetical Lectures (New Advent)