Bible Search Cross Reference 1 John 2:3. And by this we do know that we know him, if we keep his commandments.

Jeremiah 4:26. I beheld, and, lo, the fruitful place [was] a wilderness, and all the cities thereof were broken down at the presence of the LORD, [and] by his fierce anger.


http://qbible.com/references/1-john/2-3.html