Redemptive suffering is the Roman Catholic belief that human suffering, when accepted and offered up in union with the Passion of Jesus, can remit the just punishment for one's sins or for the sins of another. Like an indulgence, redemptive suffering does not gain the individual forgiveness for their sin; forgiveness results from God’s grace, freely given through Christ, which cannot be earned. After one's sins are forgiven, the individual's suffering can reduce the penalty due for sin. (From Wikipedia).
I was just just watching a debated between Richard Dawkins and a Catholic clergy from Australia and the issue of redemptive suffering came up. The concept of redemptive suffering is very close to the concept of merit in Buddhism. When it comes to lowering suffering, Buddhists start with themselves, and attempt to lower their own level of ignorance, which is the cause of suffering. In Buddhism it is believed that you should be as concerned with the suffering of others as you are with the suffering of yourself, but that you need to lower your own level of ignorance first, otherwise your attempts to lower the suffering of others will be just as likely to cause more suffering. A similar sentiment was expressed by Jesus when he pointed out that you should first remove things (logs!!???!!) from your own eye before trying to remove things from other people's eyes. This is good advice, there are many examples in Christianity of well meaning people causing great suffering by trying to "save" others, although in Buddhism it can also be (wrongly) used as an excuse to ignore the the suffering of others and to engage in a selfish (and fruitless) practice.
In Buddhism, when you have successfully lowered the suffering of yourself or another, you generate merit. Merit is used to lower the the suffering that has been banked by karma every time you acted to increase suffering in the world. It is the punishment that is in store for you for sinning (I.e., missing the mark because you acted out of ignorance). At the end of meditation, after somewhat lowering their own level of suffering, Buddhists can offer the merit that was generated to lower the suffering of others. Likewise, when a Buddhist suffers through an event without reacting out of ignorance (i.e., by loosing faith in the Dharma) they generate merit, which reduces their karmic debt.
Although both Buddhism and Christianity use an accounting metaphor, this metaphor should not be taken literally. The key is to accept the situation you are in that is causing the suffering, because you are in it and it cannot be otherwise. This will get rid of suffering due to not accepting the will of God This is sometimes referred to as the suffering of suffering in Buddhism. Basically, you’re in a bad place and stewing over whether or not that is just or right will make your suffering worse and cause you to act out of ignorance and generate more suffering. This is not easy but through practice you can get better at it and increasingly enjoy the benefits of being able to access joy and peace in the midst of suffering. The Passion of Christ is a very powerful model for this, but it is important to understand it in the right way. Jesus did not want to be crucified and prayed for a way out. Suffering is to be avoided if possible, not sought out. Remaining calm in the midst of suffering more often than not increases your likelihood of finding a way out and not making it worse. In Zen they say, plan not worry. In other words, be calm and try to find the best solution