sceptical vs unbelieving

sceptical and unbelieving both are adjectives.

Word	Noun	Adjective	Verb	Adverb
sceptical	No	Yes	No	No
unbelieving	No	Yes	No	No

As adjectives, sceptical and unbelieving are synonyms defined as:

sceptical and unbelieving: denying or questioning the tenets of especially a religion

Other synonyms of sceptical include disbelieving, skeptical.

sceptical (adjective)	unbelieving (adjective)
marked by or given to doubt	holding that only material phenomena can be known and knowledge of spiritual matters or ultimate causes is impossible
denying or questioning the tenets of especially a religion	denying or questioning the tenets of especially a religion
	rejecting any belief in gods