Faith or Fear

It has been my observation for years that many Christians make their message of none effect because of the life they live. While they proclaim that FAITH is their message, their lives proclaim that FEAR is their motivation. They do things based on some fear of something that "might happen."
When asked about their action, I usually get something along the lines of, "God gave us common sense," or, "Well, you have to be careful."
I have no problem with caution or common sense.
My problem is with the fear that masquerades as caution.
If we tell people that we have faith in the Lord, yet most everything we do is based on fear, how can we expect people to believe us? Just "believing in Jesus" is not the complete faith that we are to live. It must permeate our lives.
QUESTIONS: WHEN DOES CAUTION BLUR INTO FEAR? HOW DOES FAITH FIT IN WITH AN EXERCISE IN CAUTION?
Your comments will definitely help all of us to understand this phenomenom of an apparent dichotomy within the believing community.