I think the easiest implication to for the Christian to draw, is that the disciplines help us to be free from sin. Whether that is a specific sin like laziness, gluttony, lust, greed, fear etc. They also help us to avoid the danger of “idle hands” (Zondervan New International Version Study Bible, 2002, pp. Ecc. 10.18, 11.6). If focused upon they increase the time we spend doing the things that good Christians should be doing. They would help us to increase in certain areas like knowledge of scripture, philosophy, and time spent in prayer, fasting etc. Indeed I think Foster hints at this with his comment on “antinomianism” (Foster, 2008, p. 8) but this is not his focus. The implication Foster takes special note of is not as obvious.
He chooses to major on the transformation of the inner-man that can be brought about by such disciplines, contrasting it to the pharisaical “discipline” Jesus argued against. He makes this comparison primarily by defining the opposing views, perceptions versus regulations, and then observing the pitfalls most common with walking in the disciplines. Foster uses very “image creating” language throughout to describe the disciplines effects. For example, he uses the word “thicken” to describe how they affect his spirituality. However, as Foster explains, the disciplines help us not because they, in and of themselves, have any power.
I love Foster’s language of sewing a seed (Foster, 2008, p. 8); it’s such a “Jesus” approach. The practice of the disciplines sews us like a seed into the ground where then God can do the works of sanctification and “brought to the fullness” (Zondervan New International Version Study Bible, 2002, p. Col. 2.10). Foster notes early on that he was, despite his enthusiasm and training, unable to really help the struggling people in his congregation (Foster, 2008, p. xiv). His basic assessment was that his own spirituality was shallow (Foster, 2008, p. xv). To borrow his language of the “seed” (Foster, 2008, p. 8), he had no roots. He had to root himself through the disciplines so that God could produce fruit in his life. I believe that is Foster wants us to see the doorway of the disciplines opening to the “potter’s wheel” (Zondervan New International Version Study Bible, 2002, p. Is. 64.8), and to the dirt of God’s field of sanctification (Foster, 2008, p. 8).
Foster also remarks that the disciplines increase our want for God, quoting the psalmist, “as a hart longs for flowing streams, so longs my soul for thee Ps. 42.1” (Foster, 2008, p. 2). This I think is the heart of the whole matter that Foster wants us to see. Everything else we get from the disciplines hinges upon this truth, in Foster’s own words “The primary requirement is a longing after God” (Foster, 2008, p. 2). We must deepen our desire for the One who “makes all things new” (Zondervan New International Version Study Bible, 2002, p. 21.5) including us.