In Ecclesiazusae (169), Aristophanes (c. 446–c. 386) refers to:
νῦν εἰσὶ χρηστοί, καὶ σύ νυν χρηστὸς γενοῦ
even now they are chrestoi, and you now chrestos have become
Note that the Greek title Ἐκκλησιάζουσαι or Ecclesiazusae connotes "Assemblywomen" or "Women of Parliament" and comes from the same root as ecclesia, meaning "assembly" but also eventually denoting "church." Here we have a framework of a "church" and "christ," so to speak, eons prior to the common era.
For more uses in Aristophanes, see the Perseus Hopper.