In The Journal of Biblical Counseling, Timothy Keller makes the following observation about salt:

The job of salt is to make something taste good. I don't know about you, but I can't stand corn on the cob without salt on it. When I have eaten a piece of corn on the cob that I really like, I put it down, and what do I say? "That was great salt." No, I say, "That was great corn on the cob." Why? Because the job of the salt is not to make you think how great the salt is, but how great the thing is with which it's involved.

What if you are salt in your small group Bible study? If you're salt, people won't go away saying, "That person really knows the Bible and had all the answers. Showed me up!" No. What happens is when you go away from a small group in which you have been the salt, people don't say how great you were. They say, "What a great group." "What fascinating truth."

This is pretty simple. Salt makes you feel better about life. Christians make you feel better. But religious people always make you feel condemned. They make you feel worse.