Thematic Bible: Why the lord chastens people

It is for discipline that you endure; God deals with you as with sons; for what son is there whom his father does not discipline? But if you are without discipline, of which all have become partakers, then you are illegitimate children and not sons. Furthermore, we had earthly fathers to discipline us, and we respected them; shall we not much rather be subject to the Father of spirits, and live? read more.
For they disciplined us for a short time as seemed best to them, but He disciplines us for our good, so that we may share His holiness.

But if we judged ourselves rightly, we would not be judged. But when we are judged, we are disciplined by the Lord so that we will not be condemned along with the world.