Francis Chan and David Platt are two of the most evangelistic ministers around. They love the Gospel and are passionate about making known to the world. Listen to them, though, and hear how vulnerable speaking to someone about the Gospel is. Sometimes even terrifying. Overcoming our fear to speak is something that every disciple must do. Courage is not something that we get before we speak. Instead it is something we must pray for then find as we speak. It was even this way for Paul.
…and also for me, that words may be given to me in opening my mouth boldly to proclaim the mystery of the gospel, for which I am an ambassador in chains, that I may declare it boldly, as I ought to speak. Ephesians 6:19-20 ESV