Hebrews 12:11 "No discipline seems pleasant at the time, but painful. Later on, however, it produces a harvest of righteousness and peace for those who have been trained by it." (NIV)
Discipline: (3809 in Strong's Exhaustive Concordance): The Greek word for "discipline" is Paideia (pronounced pahee-di-ah). By implication, it means "disciplinary correction: chastening, chastisement, instruction, nurture."
Trained (1128): The Greek word for "trained" is Gumnazo (pronounced goom-nad-zo). It means "to train; exercise."
There are two ways to interpret this verse. One way is to look at discipline as a chastening from the Lord. The other way is to view it as instruction from the Lord. I believe though that these two interpretations intermingle with each other.
Discipline is a common theme in our household. We discipline the children when they do something wrong. We discpline our dog for tearing into the trash. When we do discipline, it is not for the sake of punishment. Granted, punishment may be involved so that our children will learn more about actions and consequences (the dog is hopeless), but we discipline in order to correct a behavior or action that is wrong.
Though we may be Christians, we are still human and still exercise free will. Sometimes we do things that are not in line with Abba's way, including actions that may harm ourselves or others. Since we are His children, He will discipline us in order to correct our behavior or action.
Don't think His discipline will take away our free will. We still have the choice to either accept or rebel against His discipline. When we do accept His discipline and train ourselves according to His will, we will reap righteousness and peace. Of course, when we rebel against the Lord, there is no peace because we are not in righteous standing with Him.
The other way to interpret this verse is to see discipline as instruction from the Lord. He shows us, through His Son Jesus, how we should live our lives. It is up to us to train ourselves, with the guidance of the Holy Spirit, to follow His examples, His instruction.
Whether the Lord is chastening you or instructing you, it is for the good. It may hurt, but the results will include peace and righteousness in God's eyes. As children of the Lord, that should be what we desire.