Discipline

English Standard Version Hebrews 12:8

illegitimate children

The word nothoi in v. 8 occurs only here in the Greek New Testament and should be understood in its ancient legal sense as descriptive of those who lack the privileges of family and the protection of a father1

1 Allen, D. L. (2010). Hebrews (p. 581). Nashville, TN: B & H Publishing Group.

I understand what this feels like as well as so many others.

It is a hard thing not to have a father, especially a loving and good one.

Hebrews Hebrews 12:7

In vv. 7–11, the author gives his exposition on the Proverbs text. Three points are made: the necessity of discipline; the proper response to discipline; and the benefits of discipline

Hebrews 12:7–11 ESV

It is for discipline that you have to endure. God is treating you as sons. For what son is there whom his father does not discipline? If you are left without discipline, in which all have participated, then you are illegitimate children and not sons. Besides this, we have had earthly fathers who disciplined us and we respected them. Shall we not much more be subject to the Father of spirits and live? For they disciplined us for a short time as it seemed best to them, but he disciplines us for our good, that we may share his holiness. For the moment all discipline seems painful rather than pleasant, but later it yields the peaceful fruit of righteousness to those who have been trained by it.

Three things on discipline:

Necessity

Proper response

Benefits