To persevere in one's duty, and be silent is the best answer to calumny. George Washington
Friends are as companions on a journey, who ought to aid each other to persevere in the road to a happier life. Pythagoras
Unlimited power is helpless, as arbitrary power is capricious. Our energy is in proportion to the resistance it meets. We can attempt nothing great, but from a sense of the difficulties we have to encounter: we can persevere in nothing great, but from a pride in overcoming them. William Hazlitt
If you want a quality, act as if you already have it. If you want to be courageous, act as if you were - and as you act and persevere in acting, so you tend to become. Norman Vincent Peale
Choose the course which you adopt with deliberation; but when you have adopted it, then persevere in it with firmness. Bias of Priene
It is better to turn back than to persevere in an evil course. Latin Proverb