Keep the reason rooted in the self. Have a poised mind amidst the changes of the world. Work for the fulfillment of purposes divine. Do not expect any fruit. Do everything as isvararpana (offering to God). Work in unison with the divine will, for the welfare of the world. Allow the divine energy to work unhampered through you. The moment your egoism comes in, there will be immediate blocking of the free flow of the divine energy. Make your indriya (senses) perfect instruments for his lila (work), play. Keep the body-flute hollow by emptying it of your egoism. Then the flute-bearer of Brindavan - Krishna - will play freely through this body-flute. He will work through you. Then you will feel the lightness of the work. You will feel that God works through you. You will be washed of all the responsibilities. You will be as free as a bird. You will feel that you are quite a changed being. Your egoism will try to re-enter. Be careful. Be on the alert. By gradual practice and purification of the mind you will become an expert in karma yoga. All your actions will be perfect and selfless. All actions will eventually culminate in jnana. This is the yoga of equanimity.
Fanaticism is not devotion. It is frenzy. It is mere excitement.