"Have I not commanded thee? Be strong and of good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee whithersoever thou goest." (Joshua 1:9)
I think I often forget that when Jesus reminds His followers to "be not afraid", it wasn't just good advice or mere suggestion; this is a command. When I was an unsaved man in this world, I saw things much differently than I do now. Fear was a common feeling that I dealt with daily, rejection, fear of reprimand, fear of failure, fear of the unknown, and fear of being extinguished.
It wasn't until I understood salvation and the presence of the Lord in the heart of believers did my fears begin to fade. As time wears on, I still find myself, at times, weak and absent of courage. It is in these times that we should remind ourselves of the presence of God in our heart, "for the Lord thy God is with thee whithersoever thou goest."