Para-Gram by Parmahansa Yogananda
Cheerfulness consists principally in the attitude of the mind, and is conditioned only incidentally by outside factors. Your happiness need not die, stricken by poverty, sickness, or sorrow. Realise that enough hidden strength lies within you to overcome all obstacles and temptations. Bring forth that indomitable power and energy by being cheerful at all times in spite of your circumstances. Only when you lose your mental balance are you vulnerable to suffering. If you are burned by the fire of difficulties, apply the salve of cheerfulness until your inner balance and peace are restored.