Some friends asked me the other night how I managed to appear so calm and at peace. "You study too much to be at peace...you don't sleep enough to be at peace! Why do you look peaceful?" "Well, I am," was all I could say. Any explaination I could have offered then would not have removed the confused and bewildered looks from their faces. How does one explain that true peace in life is not found in relationships with other people, or in satisfaction in one's classes or job, or "knowing yourself" or in any thing else that relies on you or anyone else. Peace come when you decide to be content with where you are in life right now, because that is where God wants you to be. It is a reliance on Him and a realization that your own efforts are not enought to gain what you naturaly desire from life. Peace is an act of the will (very much along the lines of love, in my experience). And while one may feel unhappy or restless or depressed, that act of the will, that grounding, remains.
Of course (and this is the Catholic upbringing in me coming out), one cannot find peace, nor will to be at peace, if one is in a state of sin. It just does not work. Our Lord is the only source of peace, and if one is turned away from Him, then there is no peace to be found in anything else.