Vrtrasura encouraged Indra, saying, “Don’t be morose because of my victory. There is no need to stop fighting. Instead, you should go on with your duty. When Krsna desires, you will certainly be victorious.” This verse is very instructive for sincere workers in the Krsna consciousness movement. We should not be jubilant in victory or morose in defeat. We should make a sincere effort to implement the will of Krsna, or Sri Caitanya Mahaprabhu, and we should not be concerned with victory and defeat. Our only duty is to work sincerely, so that our activities may be recognized by Krsna.

Srila Prabhupada SB 6.12.7, ppt.