Question

In the following sentence identify the main clause. Find the subordinate clause and tell if it is used as noun, adjective, or adverb .

We believe that Christianity is the key to a better world.

Main clause:
Subordinate clause type:

Answer 1

that Christianity is the key
to a better world.
adjective

Answer 2

Main clause: We believe that
Since "C is the key..." tells modifies the verb "believe," I would say the subordinate clause is being used as an adverb.