Paul wrote: “Do not be deceived: God cannot be mocked. A man reaps what he sows.”
The Dhammapada opens: “Mind is the forerunner of all actions. All deeds are led by mind, created by mind. If one speaks or acts with a corrupt mind, suffering follows, as the wheel follows the hoof of the ox.”
In Chinese: “Plant melons, get melons. Plant beans, get beans.” (种瓜得瓜，种豆得豆)
In Swahili: “He who sows the wind reaps the storm.”
The Hindu concept of karma is the most systematic elaboration: every action generates a consequence that returns to the actor, if not in this life then in the next. But you do not need to believe in reincarnation to observe that actions compound. A lie breeds more lies. A kindness breeds more kindness. A habit becomes a character. A character becomes a destiny.
This is not a promise that life is fair. It is an observation that causality is real, including moral causality. You may not see the harvest immediately. But the seeds are in the ground.