Why a Crucifixion?

Tony Jones has asked folks to submit their responses to the question: Why a Crucifixion?  

So, throughout Lent we’re going to be collecting responses to the question Why a Crucifixion? Share your answer by linking in the comment section below, tweet with the hashtag #progGOD, and email the link to progressivechristian@patheos.com.

I plan to submit a response to Tony because I appreciate the challenge to think critically and two he is giving away books!  So I am asking for you help.  What resources would you recommend in my preparation for this response?

Theories of Atonement by Allison Long Hardy
Theories of Atonement by Allison Long Hardy