faith

great trust or confidence in something or someone:

She has no faith in modern medicine.

You'll cope - I have great faith in you.

After the trial, his family said they had lost all faith in the judicial system.

Politicians must start keeping their promises if they want to restore the people's faith in government.

a particular religion:

the Muslim/Christian/Jewish/Buddhist faith

They were persecuted for their faith.

He was forced to practise his faith in secret.

a multi-faith society

They were brought up in the true faith (= the religion which the speaker believes is the only true one).