The characters literally assemble as: “Effort (功夫) does not (不) let down (负) a person with intention (有心人).”
The idiom 功夫不负有心人 is a cornerstone of Chinese cultural values related to education, personal achievement, and resilience. It reflects a profound belief in the power of human will and diligence.
This idiom is extremely common and versatile. It is used to offer encouragement, praise someone's success, or for self-motivation.
The connotation is always positive and uplifting. It is appropriate in both formal and informal settings.