Did you know that God is so holy He must put to death wickedness? 1 Chronicles 1-4

1 Chronicles 2:3
The sons of Judah were Er, Onan and Shelah; these three were born to him by Bath-shua the Canaanitess. And Er, Judah’s firstborn, was wicked in the sight of the Lord, so He put him to death.

There are not many places in God's Word where the above theme is stated.    The fact that "someone was so evil that God struck them dead" just doesn't appear much in the Holy Writ.   I can think of Acts 5 and the story of Ananias and Sapphira.   God struck them both dead for lying to the Holy Spirit, via lying to the Body of Believers.    God doesn't always strike people dead, but we ought to take note when He does.   In this long chronological list we only see Er in this framework.   To understand this we ought to consider Paul's words in Romans 9-11 in regard to Divine Election.  In that section Paul tells us that it is God's Divine prerogative to create some vessels for honor and some vessels for destruction.   When we question that Divine act and right we question the very character of God.   If God is to be God He must be perfect in His love and in His judgment.   If God were to judge unfairly He would cease to be God.   We must believe than that Judah's son, Er, was an evil man and deserved the death administrated by God.  We must also believe that since God included him in this chronological list and made mention of his death in this list, we are to pay attention and learn from it.   God does not allow wicked men to live.   All, in time, will be destroyed.   It is God's prerogative to determine the time line of that result.  We are to rest in the fact that He does these things in perfect love and perfect holiness and justice.