evangelism vs preaching

evangelism and preaching both are nouns.

Word	Noun	Adjective	Verb	Adverb
evangelism	Yes	No	No	No
preaching	Yes	No	No	No

As nouns, preaching is a hypernym of evangelism; that is, preaching is a word with a broader meaning than evangelism:

evangelism: zealous preaching and advocacy of the gospel
preaching: an address of a religious nature (usually delivered during a church service)

Other hypernyms of evangelism include discourse, sermon.

evangelism (noun)	preaching (noun)
zealous preaching and advocacy of the gospel	an address of a religious nature (usually delivered during a church service)
	a moralistic rebuke