Faithful
/ˈfeɪθ.fəl/
noun
(in the plural) The practicing members of a religion or followers of a cause.
“The faithful pray five times a day.”
Someone or something that is faithful or reliable.
adjective
Loyal; adhering firmly to person or cause.
“My dog is a very faithful dog: he doesn't like to be petted by anybody else.”
Having faith.
Reliable; worthy of trust.
“My servant is very faithful.”