Think of the last time you went to a really great restaurant. You might have praised the owner or the waiter who served you, telling them how amazing the food was. But after you left the restaurant you most likely told a friend that they just have to go try it.
Speaking to the owner or waiter was worship; speaking to your friend was evangelism. You may have said the exact same things, but your words were addressed to different audiences.
Read the whole thing here. Good stuff.