"He who heeds discipline shows the way to life, but whoever ignores correction leads others astray." -- Proverbs 10:17

There are a couple of different ways to look at "discipline".  There's discipline in the sense of consistent behavior and routine actions (the discipline of diet & exercise, reading, working, etc.), and there's discipline in the form of punishment and correction.  The first is internal-- "self"-discipline-- the other external, as when a parent disciplines a child.  Both lead to the same end, though.  Whether it's self-discipline, or submitting to corrective authority, it is for the sake of keeping us in line with healthy living and good choices.  When we are young, we have the opportunity to experience a great deal of external discipline from parents, teachers, and others in positions of authority.  As we mature, however, external discipline becomes more rare, and while we may experience this sort of discipline on rare occasion in the workplace or in society for committing crimes, if we live decent lives, others won't be disciplining us on a day-to-day basis.  Therefore, self-discipline becomes so much more important as we age.  The discipline you need to heed most is the disciplined placed upon yourself.   Decide the kind of life you're going to live, and shape your daily actions to match your heart.  This leads to the good life.

Readings: Leviticus 19:1-20:21; Mark 8:11-38; Psalm 42:1-11; Proverbs 10:17