When I was a freshman in high school I ran track with many other girls. I was one of the few Christians.
I was always very quiet and just did as I was told. In our private time after running and preparing for school I would read my bible. Unknown to me this was making an impact on some of my fellow classmates.
Later in the year two of the girls were asking questions about Jesus and what he felt about life. One of the girls asked me to lead her through the sinners prayer. She changed her life to follow Jesus Christ.
You never know the impact you are having on the world around you.