If someone should ask, “I would like to make progress in moral life; where shall I begin?”  then we would probably answer, “Wherever you will.  You can begin with a fault of which you have become conscious in your profession or occupation.  Or else you can begin with the needs of the community, with family or friends–wherever you have ascertained a failing.  Or else you may be aware that some passion has power over you, and you may strive to overcome it.  Basically, all that matters is that you should be honest and sincere and make a determined effort.”

Then one thing will lead to another.  For the life of man is a whole.  If he grasps it anywhere with determination, then his conscience awakens and strengthens his moral power in other respects as well, just as a fault anywhere in his life makes its influence felt everywhere. 

Romano Guardini, Learning the Virtues that Lead You to God, 25