We need to be careful not to misunderstand God's wrath and God's discipline as being the same thing. A lot of people assume that both are borne out of anger toward us. The truth is that God's wrath is His response to us based on His hatred of sin. Discipline is His response to us as a Father based on His love for His children.
As believers, Christ absorbed God's wrath in our place on the cross, but because we still live in sin, we get His discipline. This is God's way of lovingly chipping away everything in our lives that does not look like Him so that we can then become more and more like Christ.
“In your struggle against sin you have not yet resisted to the point of shedding your blood. And have you forgotten the exhortation that addresses you as sons?"
‘My son, do not regard lightly the discipline of the Lord,
nor be weary when reproved by Him.
For the Lord disciplines the one He loves,
and chastises every son whom He receives.’
"It is for discipline that you have to endure. God is treating you as sons. For what son is there whom his father does not discipline? If you are left without discipline, in which all have participated, then you are illegitimate children and not sons. Besides this, we have had earthly fathers who disciplined us and we respected them. Shall we not much more be subject to the Father of spirits and live? For they disciplined us for a short time as it seemed best to them, but He disciplines us for our good, that we may share His holiness. 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."
"Therefore lift your drooping hands and strengthen your weak knees, and make straight paths for your feet, so that what is lame may not be put out of joint but rather be healed.” Hebrews 12:4-13 (ESV)
The picture that this passage uses is that of a parent discipling their children. Any parent can testify that they do not take any pleasure in disciplining their kids. We do it reluctantly, yet willingly, because we love our kids, and we know that however painful it may be, we are actually protecting them from learning the lessons of life the hard way.
In the end, the goal of God's discipline is not to punish us for being sinners (Christ already took that punishment), it's to redeem us by training us for righteousness. In His discipline God is not trying to rob our joy, but rather He is trying to fulfill our joy by lining us up with the way He created things to work.
In the same way, with my kids I'm not simply punishing them because they did something bad. And my goal's not even to to simply stop them from being bad. I'm trying to teach them how to do what's right.
Unfortunately, some people misunderstand God's discipline thinking that He is angry at them and punishing them for their sin. This type of wrong thinking will only produce anger towards God and a heart that will only seek more creative ways to sin so that he won't get "caught."
"There is now no condemnation for those who are in Christ Jesus." Romans 8:1
God's goal is not to bruise us, but to heal us. He's not just trying to stop something bad from growing in us. He's also trying to plant something good within us that will grow into the "fruit of righteousness" in our lives (vs. 11). It is extremely painful to have God rip the weeds of sin out of our lives, but in the end it's the most loving thing He can do.
When Bethany was about 3 years old, we found her in front of her Nana's open pill case with medicine spilled all over the floor. Since at that age she was putting everything in sight into her mouth, we could only assume that she had ingested several pills. We immediately rushed her to the emergency room. Oblivious to what was going on, she was happy and playful as the doctors prepared the activated charcoal solution. As soon as they opened her mouth and forced the liquid down her throat, she began to cry and look at me with this, "Why are you allowing this to happen, Daddy?" look in her eyes. As much as it pained me to watch her go through something that was so scary, confusing, and uncomfortable to her, I knew I was doing it for her good. It was my intense love for her that caused me to permit something that traumatic. Knowing that there was something inside of her that could potentially kill her, the cruelest thing I could have done as her father was nothing.
God's love for us is so intense that He will lovingly discipline us (refine us) time and time again until we look like Him.