There are many phrases and quotes mentioned good and evil, I personally like these two the most.
「善惡到頭終有報, 只爭來早與來遲」 this is a 佛門諺語 (Buddhist proverb)
「善有善報，惡有惡報，若然不到，時辰未到」 this one is a 打油詩 (doggerel)
"The universe will reward good deed and punish evil deed eventually. It is just a matter of time."
「勿以惡小而為之，勿以善小而不為」 (quote from Lui Bei, Shu Han founder, 161 AD-223 AD)
"Do not think it is fine to commit a sin because it is just a minor one; Do not think it is useless to do a good deed because it is too small"
Others: ( mostly heard in martial art movies nowadays)
「改邪歸正」 (reform from wicked to decent)
「行俠仗義，儆惡除奸」( uphold justice with selflessness, deter evil and remove the wicked)
「邪不勝正」(evil cannot defeat justice)
「自古正邪不兩立」(since the ancient time, justice and evil cannot coexist)