If Peter had not failed to catch anything during the night’s fishing (cf. Lk 5:5), he would not have caught anything during the day. And if Paul had not suffered physical blindness (cf. Ac 9:8), he would not have been given spiritual sight. And if Stephen had not been slandered as a blasphemer, he would not have seen the heavens opened and have looked on God (cf. Ac 6:15; 7:56).
As work according to God is called virtue, so unexpected affliction is called a test.
God ‘tested Abraham’ (cf. Gn 22:1-14), that is, God afflicted him for his own benefit, not in order to learn what kind of man Abraham was– for He knew him, since He knows all things before they come into existence– but in order to provide him with opportunities for showing perfect faith.
Every affliction tests our will, showing whether it is inclined to good or evil. This is why an unforeseen affliction is called a test, because it enables a man to test his hidden desires.
The fear of God compels us to fight against evil; and when we fight against evil, the grace of God destroys it.
Based on St. Mark the Ascetic