“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.” Heb. 12:11 (ESV) The word “discipline” refers to instruction or training that includes correction, for example, in the raising of a child. Thus, the focus is not primarily on punishment for a wrong but rather the general overall training of a Christian, though it is painful training.
Christian training is painful (or more accurately in the Greek: grievous) for us just as children become distressed when their parents move them to do something that does not feel good to them. Therefore, as Christians we embrace, and even expect, the distaste of the challenges and sufferings that come our way. We do not avoid our training because it is our heavenly Father who is training us so he can fully restore his image in us and unite us to himself in Christ. This is the highest happiness a person can ever reach.
So, we keep our focus on Jesus and the way he is transforming our life to be more like his. Our training is like a fire that burns away our corruption. On the other side of this training we will experience greater peace for our soul since we have less inside us battling against God’s image in us and more of his nature controlling us so that our soul dwells in greater unity and harmony. Moreover, we will find that we are becoming more righteous, which means our life is more and more pleasing to God. What is a better motivation for embracing difficult training than God’s approval?