If you have ever been wronged by someone, you know two things: 1) it seems like they get away with it if we forgive, and 2) if we don’t forgive, we are the ones who suffer. However, sin, spiritual suicide, is its own punishment. Justice is found in the natural progression of events. This is not karma, but the nature of a world made good. When one sins, they violate the goodness they were created in and trade it for a much sadder world. The more we follow a path the harder it will be to escape it. Although nothing is impossible this must not be underestimated. God built justice into reality, when we go against what we were made for we find trouble. The more we go against our nature the more ends we naturally are made for will be lost. When we talk of the problem of evil and we say God permits evil to bring about a greater good, we need to also remember that to go against the way we were made is like throwing rocks in a clock tower. Eventually, events will progress to a point something highly problematic will happen. God's mercy is two-fold, 1) hopefully these things communicate to us why they are wrong and 2) to a point, damage can be healed.