You should not only know what is right but also do it.
More Hungarian Proverbs:
He tries to find his horse and is riding it.Hungarian
If it's God's will the broom will lose its handle.
Hungarian
He sweeps the problem under the carpet.
Hungarian
He who is not against us, that is with us.
Hungarian
He whets his teeth on something.
Hungarian
Even the mother cannot understand the words of a dumb child.
Hungarian