Commentaries:
Hebrews was written to a group of people who were fading away in their walk toward salvation. They were going through some pretty difficult trials, but they were not facing up to them. The underlying theme here is chastening. Many modern translations will use the word "discipline," and technically, it is closer in meaning to the Greek word.
Discipline covers formal instruction, but it also includes drill. Drill is associated with learning something repetitively—over and over again till we get it.
Discipline also includes punishment: spanking, rebuke, stern correction. Paul is saying that the sons of God should expect correction and rebuke. God has a way of starting off easy, but the punishment, the rebuke, the discipline become more stern as we fail to respond until He finally gets our attention. This could go so far as the Tribulation.
God's discipline is always corrective. He is not a sadist; He does not discipline for the fun of it. He disciplines us because we need to be turned in another direction. He is removing impediments to our spiritual development, so we do not need to become discouraged.
John W. Ritenbaugh
What Is the Work of God Now? (Part Two)
Hate in Luke 14:26 means "love less by comparison." If our love for our parents interferes with worshipping and obeying God properly, we do not genuinely love Him. Matthew 10:37 shows that Christ refers to those who place their father or mother above God in obedience and reverence; this is idolatry. The time may come when it is no longer necessary or right for us to obey our parents. Even so, we should never cease to honor them. Honor indicates a high respect for their worth, high esteem, and reverence. Without this, we cannot properly revere God. Just as our parents corrected us, so also God corrects us. As a result we honor and respect our parents, which is a shadow of our subjection to the Father.
Martin G. Collins
The Fifth Commandment
Other Forerunner Commentary entries containing Hebrews 12:9:
Habakkuk 2:2
John 15:1-8
Hebrews 10:26-27
1 John 4:8
Revelation 19:7