This is a text book example of begging the question. The conclusion is in the premises of your statement.
If I say "Yes" I have proven the premise of your question. If I say "No" I still prove the premise of your question. There is no way I can answer the question in the way it is framed without also proving the premise.
The RCC isn't lying.
Oh the RCC does lie and is lying. It lied to the authorities, it lied to the victims of abuse, it lies about salvation, it lies about Mary being co anything at all, it lies when it says we must obey the pope, it lies when it claims to be founded by Jesus and its actions prove that is a big fat lies, it lies when it says it is a shepherd. It has a long list of lies and continues to lies. Lies come from one source only.