Hello Paul, thanks for responding, my friend.
You quoted me saying "God must punish sin to protect and defend the children He loves." You responded, saying:
"This leaves no room for God's mercy."
That would be true -- if there wasn't a Cross.
Jesus suffers the punishment for sin against God's children.
God punishes the sin committed against His children in the person of Jesus.
That's mercy -- we don't suffer the punishment for the sins we commit.
God still gets His justice. But we get to be forgiven.
You said:
"We must also remember that those sinning against God's children are also God's children. Sometimes, God's command is to go and settle things with your brother. Sometimes God emphasizes restoring relationship as more important than meting out justice."
God indeed instructs us to go and settle things with others, and to restore relationships when possible.
But these things aren't opposed to justice.
God still gets justice because of Jesus. All the sins they committed against us (and that we commit against them) end up punished on the Cross of Christ.
That's why we can forgive, instead of seeking justice ourselves: justice has already been met.
That's why we can restore relationships, instead of exacting punishment from those who've hurt us: the punishment has already been meted out.
The Cross of Christ is God's mercy.
The Cross allows us to forgive and reconcile with full justice also being met.