Q. But why do you have to insist so much on God punishing us, on us making reparation?
A. Good question! And excellent choice of words!
First, God doesn't really punish us, he simply leaves us to suffer from our vices and sins. I think next to St. Augustine, Buddha has expressed this quite concisely: "You will not be punished FOR your anger, you will be punished BY your anger." St. Augustine would say "sin is its own punishment". They are both saying the same thing: actions have consequences; bad actions (that we call "sins" or "vices") have bad consequences (that we call "suffering" or "pain"). God doesn't save us from the consequences of our actions. It's part of the freedom package he gifted us.
Secondly, God is infinite perfection. One of these perfections is justice: God is infinitely just. His infinite love and infinite mercy don't negate his infinite justice any more than the finite love and finite mercy of any good parent negates their finite justice. Rather, it is precisely their love and mercy that leads them to apply their justice because is precisely "reparatory". This the word you used that made me happy: "reparation". Justice repairs. Repairs what? Repairs disorder that has been created by our sin or vice.
Best regards!
22nd November 2015