I haven't read all of the replies, but I'm sure there have been some awesome verses posted.
What I've found, in my own journey to a GBD mindset, is that I can't simply pull one or two scriptures and build my theory on that. That is exactly what the punitive minded people do, and not only is it bad interpretation to do that, but it is also very easy to slip their own agenda/opinion in there, and pretty soon it's hard to tell which is which-opinion or biblical truth.
After being handed TTUAC by a close family friend, and reading it (simply to be knowledgeable about the content and the heresy in it) I realized that I have to point him (and other punitive-minded people) to the bible in it's entirety. Yes, having a few scriptures memorized helps in the heat of the moment, and I believe that knowing them, having them posted around where you can see them, and committing them to memory is very important. However, what I have found to be even more important is to look at the character of God and then of Jesus as a whole, in all the events in the bible. When you do that, you see incredible love, mercy, grace, and forgiveness. You see gentleness coupled perfectly with firmness. You see a model for establishing boundaries, teaching (discipling) and treating others, and living a life honoring to God. THAT is what ultimately changed my mind from punitive to grace-based.
And while I still have a TON to learn, I've never had anyone argue that point with me...you simply can NOT take one or two scriptures and build a theory/method of ANYthing (parenting, marriage, work ethic, ect) from that.