good and bad deeds cancel out; merits and demerits offset each other
Idiomatic expression meaning that one's good actions and bad actions balance each other out, so neither is clearly dominant. Often used in evaluative or moral contexts.
He lived a life where his good and bad deeds canceled each other out.
There is a saying that good and bad deeds cancel each other out, but is that really true?
功罪 means 'merits and demerits' as a noun; 功罪相償う is the full idiomatic expression meaning they cancel out.
相償う is the verb part meaning 'to compensate each other'; it is not commonly used outside this idiom.
Compound of 功罪 (merits and demerits) + 相 (mutually) + 償う (to compensate). The exact historical origin is uncertain, but it follows a classical Chinese-derived pattern of four-character idiomatic expressions.