Theoretical or Practical Knowledge?

J. Gresham Machen, in his classic, Christianity and Liberalism, makes a helpful distinction related to the difference between theoretical and practical knowledge. He says:

"Certainly no part of Jesus's knowledge of God was merely theoretical; everything that Jesus knew about God touched his heart and determined his actions. In that sense, Jesus's knowledge of God was 'practical.' But unfortunately that is not the sense in which the assertion of modern liberalism is meant. What is frequently meant by practical knowledge of God in modern parlance is not a theoretical knowledge of God that is also practical, but a practical knowledge which is not theological--in other words, a knowledge which gives no information about objective reality, a knowledge which is no knowledge at all. And nothing could possibly be more unlike the religion of Jesus than that."

J. Gresham Machen, Christianity and Liberalism, 58.