What does Hebrews 12:10 mean?

In this passage, the writer explains why Christians should embrace the idea of being "disciplined" by God. This certainly takes the form of correction and conviction when we sin, but it can also involve earthly hardships. In some cases, these trials can be extreme (Hebrews 11:35–38), but they are not always so dire (Hebrews 12:4). Jesus' attitude is, as expected, the proper response to these kinds of struggles: to trust that God is working out all things for the sake of future joys (Hebrews 12:2). Good parents discipline their children, so spiritual discipline from God is a sign of His love for us (Hebrews 12:5–6). In contrast, those who experience no such correction from God have good reason to question their spiritual state (Hebrews 12:8).

The prior verse connects with these words, supporting the idea that discipline is a sign of good parenting. As stated earlier, children eventually come to respect the guidance of their parents (Hebrews 12:9). Since we can see the benefit of earthly parenting, we ought to be all the more receptive to our Divine Parent! Here, this idea is echoed by pointing out that the discipline we receive from earthly parents is according to their knowledge and understanding. God's knowledge and understanding is far more extensive (Isaiah 55:9), so we should be that much more willing to honor and obey it.

This verse also re-emphasizes the purpose of God's discipline. Even when the discipline is dire (Hebrews 6:7–8), God's intent is to make us more like Him—to share in his Holiness. As the next verse admits, we never "like" that discipline, but we can understand and accept it.