“When evil people are not punished right away, it makes others want to do evil, too.”
(Eccl 8:11NCV)
According to Scriptures, God is a good and compassionate God, who is slow to get angry and quick to forgive sins (Ex 34:6-7; Micah 7:18). Nevertheless, there are times He moves in very quickly to punish people for their sins, giving them no warning and leaving them no room for repentance.
For instance, when Nadab and Abihu, two of the sons of Aaron, offered an unauthorized fire before the Lord, they were both instantly consumed by fire from the presence of the Lord. They did not get any warning; neither were they given any opportunity to ask for forgiveness. They were simply executed by God instantly. The experience so shocked Aaron, their father, that he was speechless. (Cf. Lev 10:1-3)