Seduction And Trial

Sed dices: ut quid talem potestatem Deus diabolo dedit ad seductionem humanam? si enim ille seductionis potestatem non accepisset, tu probationis mercedem habere non poteras. Nisi enim infideles reliciti fuerunt, non eliguntur fideles. Nisi aliquorum facta fuerit refutatio, aliorum non potest fieri electio. Omnis enim seductio non potest esse seductio, nisi habuerit boni colorem, per quod videatur bonum esse quod malum est: et tunc non tantum speciem primam rerum bonarum aspicias, sed causam rerum consideres. Omne enim malum voluit Deus posse latere sub colore boni, et omne bonum voluit esse sub caligine obscuritatis, ut tu nec bonum sine laboure invenias, nec malum sine labore evites: neligens autem nec bonum inveniat, nec malum evadat. Omnia Deus posuit in labore, ut in omni re mercedem praepart, sicut ait Salomon: Quoniam Deus distensionem magnam dedit hominibus, ut distendantur in ea. Et Job Omnis vita nostra tentatio est. Opus Imperfectum in Matthaeum, Homilia XXI Source: Migne PG 56.783-4

But you may say: 'Why did God give the devil such power for the corruption of men?' Because if he had not received the power of seduction, you would not be able to have the reward for trial. For unless the faithless shall fall away, the faithful shall not be chosen. Unless there is the refutation of a certain number, the election of others is not possible. Then there is no possibility of seduction unless it shall take on the colour of the good, by which that which is evil seems to be good. Thus you should not only consider the first sight of good things, but look to the root of them. For God has allowed every evil to be hidden beneath the appearance of good, and every good to be covered by a dark obscurity, so that you do not find good without toil, nor do you avoid evil without labour, whence the negligent neither find good, nor do they escape evil. For God has set a labour in all things, that in everything reward may be prepared, as Solomon says, 'Because God has given a great labour to men, that they be exercised in it.' 1 And Job says 'Our whole life is trial.' 2 Opus Imperfectum on Matthew, from Homily 21 1 Eccl 3.10 2 Job 7.1