The author attempts to emphasize the importance of the Reformed doctrines of grace. He focuses specifically on the teaching of total depravity. It is based on Scripture's teaching that God saved us while we were yet dead in our trespasses (Ephesians 2:1). In the final place, the author emphasizes the importance of equipping believers with these teachings so that they can be able to teach them to others.
Why do we possess imagination? Imagination is what characterizes humans because it is a gift from God. It is given so that we can understand God, defend the faith and evangelize others.