When I was thinking about John the Baptist being a missionary, here are the characteristics that stood out to me:

John preached with boldness (Matthew 3:1, 2; John 1:29-37).

He knew Christ was the focus and not himself (John 1:20-23; John 3:28-30).

Sometimes John doubted, but he always trusted Jesus' direction (Luke 7:19-28).

All good characteristics for a missionary.

by: http://www.whatchristianswanttoknow.com/missionaries-in-the-bible-10-to-emulate/#ixzz4Bj7oKEHK