It is plain that the power to distinguish and discriminate...
It is plain that the power to distinguish and discriminate makes possible the existence of good and evil, of beauty and ugliness. By giving man the inestimable blessing of freedom and the ability to choose, God, whose wisdom is manifest throughout creation, wished to display fully His ability to create phenomena bearing witness to His wisdom and power.
He placed within man's being the possibility of doing both good and evil, and although He compels him to do neither, He always expects him to do good. God does not approve of evil; it is righteous conduct that meets with His approval and, in exchange for which He provides abundant, unimaginable reward. God warns man against following the path of evil and threatens him with punishment and torment if he does so.
Thus, by using the power of choice that God has bestowed on him, man can act as he should, conforming both to divine guidance and to his own conscience. But, if occasionally his foot should slip and he should commit some sin, the path remains open for him to return to purity and light, to God's favor and mercy. This is in itself a further manifestation of God's generosity and all-embracing justice, one more of the blessings He bestows on His servants.
Were God to give immediate reward to the virtuous for their righteous conduct and acts, they would not in any way be superior to the corrupt and the sinful. And if the evil in thought and in deed were to be always met with instant punishment and retribution, virtue and purity would not enjoy any superiority in this world to vice and impurity.
***** The principle of contradiction, is, in fact, the basis of the created world; it is what enables matter to change and evolve so that God's grace flows through the world. Were matter not to take on different shapes as a result of its encounter with various beings and were being unable to accommodate new forms within itself, the differentiation and advancement of being would be impossible. A stable and unchanging world would resemble stagnant capital that produces no profit.
For creation, change is the capital that brings about profit. It is, of course, possible that the investment of a certain portion of capital should result in loss, but the constant motion of matter as a whole definitely results in profit. The contradiction that takes place in the forms of matter results in the advancement of the order of being toward perfection.