heathenism vs pagan religion

heathenism and pagan religion both are nouns.

Word	Noun	Adjective	Verb	Adverb
heathenism	Yes	No	No	No
pagan religion	Yes	No	No	No

As nouns, heathenism and pagan religion are synonyms defined as:

heathenism and pagan religion: any of various religions other than Christianity or Judaism or Islamism

Other synonyms of heathenism include paganism.

heathenism (noun)	pagan religion (noun)
any of various religions other than Christianity or Judaism or Islamism	any of various religions other than Christianity or Judaism or Islamism