A common saying goes, “Good will be rewarded with good, and evil with evil.” Then why doesn’t God destroy all the wicked?
The answer from God’s word:
“Today, regardless of their actions, and provided they do not obstruct God’s management and have nothing to do with the new work of God, such people will not be subjected to the corresponding retribution, for the day of wrath has yet to arrive. There is much that people believe God should already have dealt with, and they think that those evildoers should be subject to retribution as early as possible. But because the work of God’s management has still not come to an end, and the day of wrath has yet to arrive, the unrighteous still continue to perform their unrighteous deeds. … Now is not the time for man’s punishment, but the time for carrying out the work of conquest, unless there are those who impair God’s management, in which case they will be subjected to punishment based on the severity of their actions.”
from “God’s Work and Man’s Practice” in The Word Appears in the Flesh