unity
I think you meant to refer to "community" as in the place where the solidarity is taking place? Unity and solidarity mean almost the same thing so you more than likely got confused when it came to word usage.
member liability
Liablity is a negative term. I think you were again, trying to say "ability". Please do not keep using English words without being certain of the meaning. It affects the clarity of your sentence and also, shows a limited English vocabulary ability. Build your vocabulary properly. Use a dictionary before using the word. Be sure of the meaning.
The errors in this writing are pretty basic for ESL students. It is nothing that you cannot overcome in due course. Read more in English and never stop writing. You need to make mistakes in order for people to help you see the errors and correct them.