Accidents will happen.
天有不测风云。
A clean hand wants no washing.
身正不怕影子斜。
A clear conscience is a soft pillow.
问心无愧，高枕无忧。
A clear conscience is a sure card.
光明磊落，胜券在握。
A clear fast is better than a dirty breakfast.
宁为清贫，不为浊富。
Actions speak louder than words.
事实胜於雄辩。
Admonish your friends in private, praise them in public.
在私底下要忠告你的朋友，在公开场合又表扬你的朋友。
A fair face may hide a foul heart.
人不可貌相。
A faithful friend is hard to find.
益友难得。
A fall into the pit, a gain in your wit.
吃一堑，长一智。