also: エヴァンジェリスト
noun
A person who enthusiastically promotes a particular cause, product, or technology, often in a business or tech context. Also used in a religious sense for a preacher of the Christian gospel.
彼は新製品のエバンジェリストとして世界中を飛び回っている。
He travels around the world as an evangelist for the new product.
In the tech industry, evangelists play an important role.