You can't. No, it's not useless. If you fight Flavius, He takes out 30 morale. If he has more stars than your hero, he takes out 60 morale.

If Herja hits you and you have 100 morale, none of your heroes will skill.

So you better have at least 160 morale. Don't worry, you'll get that when you improve your endurance runes later on.

What's useless are morale saintings. If you get one, imo you should pay gems to get rid of it ASAP.