What was most telling about the disagreement between the two men was their discussion of Luke 4. Mohler argued the passage should be understood in light of how he interpreted the preaching and teaching of Paul and the other apostles. This means that when Jesus said that he came to bring good news to the poor that good news was personal salvation.
Wallis argued that yes, personal salvation is one part of that good news, but that the other part is the Kingdom of God breaking into the world and transforming societal relationships as well. When the Gospel is proclaimed, it is good news for a poor person's entire being, community and world -- not just his or her soul.
First, it was encouraging to hear Mohler spend a lot of time emphasizing that working for justice is essential to fulfillment of the Great Commission. Throughout the night he repeated his concern that a lot of Churches are REALLY bad at making disciples who actually do the things Jesus told us to do. As the president of one of the largest seminaries in the world, it will be interesting to see if he is able to train a generation of pastors who will do things differently. My concern is that he is missing the connection between his theology and the failure of Christians to actually do justice.