Hebrews 12:11

‘All chastening seems for the present to be not joyous but grievous; yet afterward it yields peaceable fruit to those who have been exercised by it, even the fruit of righteousness.'

He recognises that chastening is never pleasant. Indeed when it is in process it seems grievous. It can hurt dreadfully. But it is the result that we should consider, not the process. To those who respond to God's chastening rightly, and are rightly affected by it, it yields ‘peaceable fruit', the peaceable fruit ‘of righteousness' (compare James 3:17). Just as earthly chastening should result in the restoration of our relationship with our parents, restoring peace between us, so does our Father's chastening result in the restoration of our present ongoing relationship with Him when it is in danger of breaking down. The fruit of His discipline is that we are found at peace with Him, and receive peace from Him. And this will result in our continuing to be truly righteous inasmuch as we respond to it. So God's purpose in chastening us is in order that we might be at peace with Him, and so that we might become ever more holy and righteous. We have been perfected in holiness (Hebrews 10:14) that we might be made holy, (totally separated to a holy God). For without the latter, first imputed and then imparted, the fullness of the former is impossible.

‘Exercised thereby.' The word is taken from training for the games and stresses the great effort to be put in. God's chastisement should result in our getting fit in our hearts in order to be righteous, with its resulting fruit.

So Let Them Now Be Responsive To Their Father's Chastening Instead of Rebelling Against It (Hebrews 12:12).

In the light of the fact that they now see their tribulations as in fact being their Father's chastening, let them now fully respond to it and get their attitudes and response right, for then all will turn out well.