Οὐ γὰρ τὸ δεσμεῖσθαι λυπηρὸν τοῖς διδασκάλοις ὑμῶν, ἀλλὰ τὸ μὴ ὁμονοεῖν τοὺς μαθητάς. Τοῦτο μὲν γὰρ καὶ ἐπίδοσιν τῷ Εὐαγγελίῳ δίδωσιν, ἐκεῖνο δὲ διασπᾷ.

For it does not grieve your teachers to be imprisoned, but it grieves them that the disciples do not agree. For the former serves to advance the Gospel, the latter tears it apart.

-John Chrysostom Homiliy 1 on Philippians