A proverb meaning 'not everyone in the world is cruel' — there are kind people out there, so don't distrust everyone.
困っていたら助けてくれる人がいるよ。渡る世間に鬼はないから心配しすぎないで。
If you're in trouble someone will help you. Not everyone in the world is cruel, so don't worry too much.
彼は最初は人を信用しなかったが、いい人に出会って『渡る世間に鬼はない』と言った。
At first he didn't trust people, but after meeting a good person he said, 'Not everyone in the world is cruel.'
ボランティアに助けられて、渡る世間に鬼はないと感じた。
Being helped by volunteers made me feel that not everyone in the world is cruel.