Focus does three things for you:
1) It keeps you on target. We find ourselves pulled in a dozen different directions, spending much of our time and energy on things we don't really care about. Author Don Marquis put it this way: 'Ours is a world where people don't know what they want, and are willing to go through hell to get it.' The Bible says: 'Let your eyes look straight ahead...Do not swerve to the right or the left' (Proverbs 4:25-27 NIV).
2) It increases your energy. Attempting everything, like attempting nothing, will suck the life out of you. Focus gives you energy. Admiral Richard Byrd, the Polar explorer, said, 'Few men come anywhere near exhausting the resources dwelling within them. There are deep wells of strength that are never used.' One of the reasons those wells go untapped is lack of focus. The mind doesn't reach toward achievement until it has clear objectives.
3) It lifts you. It's been said that 'the world stands aside to let anyone pass, who knows where he or she is going.' In a sea of mediocrity, just knowing what you want to do and making an effort to pursue it, distinguishes you from almost everybody else. Henry David Thoreau asked, 'Do you ever hear of a man who had striven all his life faithfully and singly toward an object, and in no measure obtained it? If a man constantly aspires, is he not elevated?' Just by striving to become better than you are, you become elevated even if you don't accomplish what you desire, and even if others don't step aside for you. By trusting God and aiming higher, you move to a higher level.