Proverbs 13:21 Notes
Evil pursueth sinners: but to the righteous good shall be re-payed.
Since sinners willfully live in sin. Not only will they do evil, but evil will certainly happen to them. Just as they wish to commit evil, evil will fall upon them. This is only common sense. After all; "if you play with fire, you will get burnt." Righteousness brings favor from man and God. His recompense is honor and salvation. The righteous are greatly paid for their good.
Reference: Proverbs 23:16-18 Proverbs 1:9-11 Proverbs 14:22 Proverbs 16:20 Romans 2:5-9