Forgiveness is not in any way saying something is okay or acceptable, nor is it saying that you deny appropriate justice. It's not even pretending something didn't happen—it totally happened and it definitely sucked.
What forgiveness is, is simply releasing someone from their debt. It's saying that the sin they committed is no longer held over them, for you have freed them from what was owed you.
Forgiveness and peace are not some masochistic way of embracing violence or seeking it out. This is a common misconception of Christian pacifism. People think we're somehow advocating that you should go get beat up by others and be all lovey-dovey and subject yourself to horrible situations without even trying to avoid them. But to quote Derek Flood, "The goal of enemy love is not to subject oneself to violence, but to act to break the cycle of violence" (Derek Flood, Disarming Scripture, p 191).
Jesus never said, "If someone molests you, forgive them and pretend it didn't happen and stick around." Absolutely not! Jesus came to set the captives free, not subject them to a theology of repetitive violence. Pacifism means embracing peace, love, and forgiveness over violence, hatred, and bitterness and it means doing it as many times as a sin is committed against you.
Pacifism and forgiveness still seek justice. The judgment and ruling of courts and judges and juries are completely acceptable—so long as a death sentence is not the answer, for Christians are to be pro-life in all ways, knowing redemption is always possible. Prison is still a possibility. Creative ways of making amends are still a possibility. God is a God of justice just as he is a God of forgiveness. Forgiveness is not a way of allowing us to get away with things.
We often misunderstand what justice is as well, because we usually turn it into revenge. For example, I once felt that some injustice had been done to a friend of mine and I wanted to raise awareness so that those who had committed the injustice would have to face themselves. I called my friend looking for their opinion as to how far I should go to find that justice.
“Well, how bad do you want to get back at them?” they asked.
“I’m not trying to get back at anyone!" I laughed. "I’m just trying to find justice.”
“Right," they paused. "So how much justice do you want?”
I laughed again. We use the words so interchangeably and think of them as the same thing, but they're not. Justice is done in love, revenge is done in hatred. Justice is done in righteousness, revenge is done in unrighteousness. Justice is done in peace, revenge is done in violence. Justice is what's right in God's eyes, revenge is what's right in ours. We must be people of justice, not of vengeance, for Christians are to have nothing to do with vengeance (Ro 12:19).