The word is 'discipline.'
But I keep under my body, and bring it into subjection: lest that by any means, when I have preached to others, I myself should be a castaway. - 1 Corinthians 9:27
A lot of challenges your way. There will be moments when you will want to question your purpose, your course, your entire destiny - but bind your mind to discipline. Be energized and stay the course. You will attain your goal!