一句关于勇气和信心的英文名言或者俗语?

Nothing in the world is difficult if you set your mind to it.世上无难事,只怕有心人.Pull up one's socks振作起来；鼓起勇气（误：提起袜子）Where there is a will,there is a way.有志者事竟成.Where there is...