Here are some useful ways for talking about what you believe and don’t believe in.
I believe in… (the importance of free speech)
I’m a (great / firm) believer in … (fresh air and exercise)
I’m convinced that… (there’s a solution to every problem)
I’m passionate about… (human rights)
I’m committed to … (working towards peace)
I don’t believe in …
I think that … is complete nonsense / doesn’t make sense
Giving a reason for your beliefs
There must be / can’t be .. (life after death) because otherwise…
There’s no evidence for / to support … (an afterlife)
There’s no other way to explain / account for …
Talking about your religious beliefs
I’m a practising (Catholic, Muslim, Jew etc).
I’m a non-observant / lapsed Catholic.
She’s a devout (Christian, etc).
I’m a “don’t know”.
I’m an agnostic.
I’m an atheist.
He’s an extremist / fundamentalist / evangelist.
Talking about your political beliefs
I support / back (the Labour Party).
I’m a Conservative / Liberal / Socialist / Labour Party supporter.
I’m a life-long (Conservative / Labour Party supporter).
I’ve always voted (Tory, Liberal etc).
He’s a staunch Conservative.