If you are prepared, you have nothing to worry about; a proverb advising that preparation prevents worry or trouble.
旅行前に地図や持ち物を確認しておくのは大切だ。備えあれば憂えなしだよ。
It's important to check the map and belongings before a trip. If you're prepared, you won't worry.
災害用の備蓄をしておけば安心だ。備えあれば憂えなし、というだろう。
Keeping disaster supplies gives peace of mind. As they say, if you're prepared you have nothing to worry about.
試験に向けて毎日少しずつ勉強する。備えあれば憂えなしだ。
I study a little every day for the exam. If you prepare, you won't have to worry.