On today's episode of Theology Simply Profound, Rob and Bob continue their discussion about the doctrine of the atonement. Today we take a closer look at the concept of penal substitution. In doing so, we review some of the other theories of the atonement. But what does the Bible say about the nature of Christ's cross? What does it do? What is meant by penal substitution? Is it necessary? What biblical texts teach us about penal substitution?