Redemptive suffering is the concept of being able to suffer for someone else’s benefit. It is the basis of Jesus’ death on the cross: God took on human flesh man so that He could suffer in His human nature (His divine nature is perfect, so it could not suffer). That suffering was not for some sadistic purpose; rather, it was for atonement. Jesus died on the cross to help us. His death paid the debt of our sins. The picture above is of the “scapegoat” the animal in Jewish culture on whom the people’s sins were cast and who was driven away into the desert (a foreshadowing of Jesus who would really take the people’s sins away). Every imperfect act of ours separates us from God (who is ultimate perfection) and makes us the devil’s property (think of Edmund in the Lion the Witch and the Wardrobe–see the video below, particularly 3:20-5:20).
Sin also enslaves us–it is truly addicting (when we sin, it becomes more habitual to sin again and easier to sin more gravely). Prior to Jesus’ death, we had no way of repaying the debt of our sins, so even those “good” people still committed some sins in their lives, and their souls were not in a state where they could enter Heaven.
God loves us so much that He became one of us in order to die for us (see the rest of that movie clip, understanding Aslan as a representation of Jesus). Jesus’ death is applied to us particularly through the sacraments. In the Sacrament of Baptism, we are washed with water, but it is not just symbolic; it actually affects our souls. When someone is baptized, he is drowned; His life that he lived up to that point is ended–including all sin (Original Sin, which we inherit from Adam and Eve, and any actual sins, which we have committed up to that point)–and he is raised to a new life for God. The Sacrament of Reconciliation (Confession) applies Jesus’ death on the cross to us to forgives us of any sins we commit after Baptism (provided that we are humble enough to own up to them, that we tell them to God through one of His priests, that we are sorry, and that we intend to try not to do them again). The Sacrament of Holy Communion (the Eucharist) is the main sacrament. It is the bread and wine that are changed into Jesus’ Body and Blood at Mass every day. Jesus’ sacrifice on the cross is made present on the altar at every Catholic Mass. That sacrifice is re-offered to the Father, and then we are allowed to partake in it. We consume what used to be bread/wine and has now become Jesus’ Himself. We eat His living Flesh (offered for us) and drink His living Blood (shed for us) under the appearance of bread and wine. God became man to die for us and give us these sacraments (and the 4 others, which I won’t go into here).
In the same way, God also allows us to suffer for others. In our pain (of whatever sort: mental, physical, social, etc.), we can unite ourselves with Him on the cross and offer that suffering as a sacrifice to help other people. We understand that all suffering we go through now is trivial compared to the complete joy to be experienced forever in Heaven or (conversely) the complete agony to be experienced forever in Hell. We welcome suffering insofar as it makes us more like Jesus, who suffered for us, and enables us to suffer for others. Though I may have great pain in suffering (and I may lose a lot of temporal goods), it is worth it to save someone’s soul from eternal damnation. The suffering through which I go, I can offer up to God because He often wishes to use us as tools for bringing about His mercy. In His mercy, He might grant some sinner extra graces to see the wrongs in his actions, and recognize the harm he causes through his sins. This may be enough for the sinner to repent, to turn back to God and seek forgiveness. That may ultimately lead the sinner to be in Heaven instead of Hell for all of eternity. Thus, the sacrifices we Catholics offer up to God are acts of love–to love is to will for what is ultimately best for someone. While I may not like the daily trials which life throws at me, I recognize that they are opportunities to love people (those around me, or those whom I may never meet). They are opportunities to offer myself up and take their punishment on my flesh, so that they might one day return to a relationship with God avoid eternally separating themselves from Him: “Greater love has no man than this, that a man lay down his life for his friends.” [John 15:13]