本性难移

江山易改，本性难移。

jiāng shān yì gǎi, běn xìng nán yí.

Rivers and mountains are easy to change, but one's nature is hard to move.

常言道江山易改本性难移，但良好的社会环境与严格自律能够引导人性向善。

cháng yán dào jiāng shān yì gǎi běn xìng nán yí, dàn liáng hǎo de shè huì huán jìng yǔ yán gé zì lǜ néng gòu yǐn dǎo rén xìng xiàng shàn.

As the saying goes, it is easy to change one's nature but hard to change one's nature, but a good social environment and strict self-discipline can guide human nature to be good.