Pastor David Huffstutler provides a shapshot answer at Religious Affections Ministries.
From this terribly brief survey, we could at least say that an evangelist is someone who takes the gospel to those who have not heard it before, whether it be to one person at a time, or large crowds within a given city. It is someone who does not stay long in one place, likely leaving behind planted churches so that he can take the gospel to new places that have never heard it before. And yet, he is also someone who ministers to the saints by equipping them for the work of the ministry, likely teaching them to do what he himself is specially gifted to do, namely, persuasively giving the good news of the gospel to unbelievers.
