The chorus in Oedipus Rex represents the Theban elders. The chorus's interest lies purely in protecting the city; and with this interest in mind, the chorus shows great respect and admiration for their king, Oedipus, and also great reverence for the gods. Also, with the interests of the city in mind, they serve the role of portraying a far greater understanding of humanity than Oedipus does.
In each ode, the chorus shows either great reverence for the gods or great respect for Oedipus. The chorus is well aware that the citizens of Thebes need the gods' protection in order to be healed from their current plague. The chorus portrays its belief in the gods' power and calls on the gods to use their power to heal the city, as we see in the chorus's lines:
I call: my threefold protection from death [Zeus, Athena, Artemis], shine forth on me. If ever when madness was set upon the city, you sent away our burning scourge. (175-177)
Not only does the chorus call upon the gods for the city's protection, the chorus is also far quicker to recognize irrational behavior than Oedipus is, which also stems from the chorus's drive to heal and protect the city. In its ability to recognize irrational behavior, the chorus is better able to perceive the weaknesses of human nature than Oedipus is. One example is seen when Oedipus reacts to Tiresias's horrible prophecy. Oedipus becomes furious and even accuses both Creon and Tiresias of a treasonous plot. The chorus is very quick to recognize that Oedipus is behaving irrationally and that the most important thing is learning how to heal the city, as we see in the chorus's lines, "To us it seems that both this man's words are your own, Oedipus, were said in anger" (424-425).
However, despite the fact that the chorus recognizes Oedipus's human failings, they remain respectful to their king and find it very difficult to believe that Oedipus is guilty. Instead, very rationally they argue that there is no guarantee that the seer is truly wiser than the chorus is and until they see proof, they will not allow Oedipus's good name to be slandered. The chorus's rational mind serves to represent a greater understanding of humanity than Oedipus has himself.