Hebrews 12:4-11
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)

Hebrews addressed people fading in their walk toward salvation, enduring difficult trials without facing them. Chastening, closer in meaning to "discipline," comes from the Greek paideuo, an active training directed toward moral and spiritual development to influence conscious will and action. It includes formal instruction, repetitive drill until a lesson is learned, chastisement (spanking, rebuke, stern correction) for those who refuse to get it, and encouragement. In a religious sense, it educates someone to conform to divine truth. God's sons should expect correction. He starts easy, but discipline grows sterner when they fail to respond, even extending to the Tribulation. Never sadistic, His discipline is always corrective, turning His sons in another direction and removing impediments to spiritual development, so discouragement is unnecessary.