There's an old saying, that you really don't know something unless you can teach it. This has never been more true especially with the gospel.

So how well do you know the gospel? Do you share and teach it clearly?  Sometimes believers carry a lot of "intellectual" baggage with them and what may seem clear to them, can be very unclear to the recipients. Other times people have been influenced by other believers and speak using "Christian lingo" which might as well be Greek to the unbeliever. 

So the goal is to preach it, teach it, and share it with clarity. Keeping it simple also has another side effect, which is gaining confidence...you'll realize "I can do this!"