Regarding being afraid when sharing Christ:
I find there are many people that don't feel comfortable, or adequate is sharing Christ. There is a fear factor, but much of the problem is just not wanting to do it.
This is not normally a knowledge problem. I know in my life I have been to many conferences, seminars, classes, sermons, books and lessons. And with all of these I leave not ready to share Christ. The problem is not knowledge, it is a problem of the heart. When I got my heart right then I was ready to share Christ.