Here reading, punctuation, and sense are obscure.  The Ben. Ed. have ἔξω μὲν ὄντες, τῆς κοινωνίας εἴργονται, and render “Si sint quidem laici, a boni communione arcentur.”  But ἔξω ὄντες, standing alone, more naturally means non-Christians.  Balsamon and Zonaras in Pandects have ἔξω μὲν ὄντες τῆς ᾽Εκκλησιας εἰργονται τῆς κοινωνίας τοῦ ἀγαθοῦ.