1 Corinthians 9:24-27 (NIV) 24 Do you not know that in a race all the runners run, but only one gets the prize? Run in such a way as to get the prize. 25 Everyone who competes in the games goes into strict training. They do it to get a crown that will not last; but we do it to get a crown that will last forever. 26 Therefore I do not run like a man running aimlessly; I do not fight like a man beating the air. 27 No, I beat my body and make it my slave so that after I have preached to others, I myself will not be disqualified for the prize.
1 Timothy 4:7-8 (NIV) 7 Have nothing to do with godless myths and old wives' tales; rather, train yourself to be godly. 8 For physical training is of some value, but godliness has value for all things, holding promise for both the present life and the life to come.
2 Timothy 1:7 (NIV) For God did not give us a spirit of timidity, but a spirit of power, of love and of self-discipline.
Galatians 5:23 (NIV) 23 [G]entleness and self-control. Against such things there is no law.
Beware of saying, "I haven't time to read the Bible, or to pray"; say rather, "I haven't disciplined myself to do these things." Oswald Chambers (1874-1917)