The salt of the earth
Definition 1 of 1
Pro Tip 1/3Positive Connotation
The phrase implies deep admiration for someone's good qualities and morality. 
After volunteering for years, Mark has shown he's truly the salt of the earth.
Pro Tip 2/3Idiomatic Usage
Used to emphasize someone's goodness, it's not about the literal taste of salt. 
This community is full of people who are the salt of the earth.
Pro Tip 3/3Figurative Meaning
It's a metaphor for describing a person with great virtue and worth. 
The local baker, always giving to charity, is the salt of the earth.