Several quotes about battles.

This is as true in everyday life as it is in battle: we are given one life and the decision is ours whether to wait for circumstances to make up our mind, or whether to act, and in acting, to live.

Omar N. Bradley

Happiness is dependent on self-discipline. We are the biggest obstacles to our own happiness. It is much easier to do battle with society and with others than to fight our own nature.

Dennis Prager

Be kind, for everyone you meet is fighting a hard battle.

Philo

To be nobody but yourself in a world which is doing its best, night and day, to make you everybody else means to fight the hardest battle which any human being can fight; and never stop fighting.

e. e. cummings