Spiritual discipline makes us spiritually fit. It's in the Bible, I Timothy 4:7-8, TLB. "Don't waste time arguing over foolish ideas and silly myths and legends. Spend your time and energy in the exercise of keeping spiritually fit. Bodily exercise is all right, but spiritual exercise is much more important and is a tonic for all you do. So exercise yourself spiritually, and practice being a better Christian because that will help you not only now in this life, but in the next life too."
What does spiritual discipline do for us? It helps us focus on running the race of life. It's in the Bible, I Corinthians 9:24, TLB. "In a race everyone runs, but only one person gets first prize. So run your race to win."
Spiritual discipline strips away the nonessentials. It's in the Bible, Hebrews 12:1, TLB. "Since we have such a huge crowd of men of faith watching us from the grandstands, let us strip off anything that slows us down or holds us back, and especially those sins that wrap themselves so tightly around our feet and trip us up; and let us run with patience the particular race that God has set before us."