One of the fundamental roles of the Chorus in Euripides's work is to provide a counterpoint to the forces of doubt and skepticism towards the divine. Euripides himself was not very fond of the Chorus, and rather sought to minimize their role in driving the action of the narrative.  Euripides entrusted that to his characterizations and plot.  The Chorus though functions as a continual point of reference of submission to the divine.  The Chorus embodies the lack of hubris and the devotion to the divine.

The Chorus operates in contrast to the skepticism and judgment of Pentheus. As a king, Pentheus refuses to acknowledge any divine right to Dionysus.  He also terrorizes anyone who pledges loyalty to Dionysus, imprisoning both followers and the God himself.  For Pentheus, there is a rejection in the power of the divine, and a lack of acknowledgement that Dionysus is worthy of divine respect.  Pentheus has a disdain for Dionysus and demonstrates zeal in targeting him for arrest:

And seek amain this girl- faced stranger, that hath wrought such bane to all Thebes, preying on our maids and wives Seek till ye find:  and lead him here in gyves, Till he be judged and stoned and weep in blood The day he troubled Pentheus with his God.

Pentheus shows a lack of faith and respect towards the divine in terms of his attitude towards Dionysus.  

It is to this end that the Chorus functions as the opposite.  Throughout the drama, the Chorus consists of devotees, the Bacchae, who believe in Dionysus:

He loves goddess Peace, who brings prosperity and cherishes youth. To rich and poor he gives in equal measure the blessed joy of wine. But he hates the man who has no taste for such things—to live a life of happy days and sweet and happy nights, in wisdom to keep his mind and heart aloof from overbusy men.

The Chorus operates as devotees of the divine Dionysus. Even when it is evident that Pentheus's wrath against Dionysus knows no end, the Chorus pleads to their chosen force of the divine for restoration and deliverance from malevolence:

Lo, we race with death, we perish,
Dionysus, here before thee!
Dost thou mark us not, nor cherish,
Who implore thee, and adore thee?
Hither down Olympus’ side,
Come, O Holy One defied,
Be thy golden wand uplifted o’er the tyrant in his pride!

The adoration and devotion that the Chorus holds towards Dionysus is one of their primary functions of the drama.  They represent the devotion that human beings must show towards the divine, something that Pentheus and those who deny Dionysyus' rightful place lack.  The Chorus functions as the one group who is spared the vengeful wrath of Dionysus towards those who discredit and disrespect him.  The Chorus place of devotion and awe that they display towards Dionysus is one of their primary functions of the work.  Their role is to remind human beings of the potential for disaster when hubris or pride causes one to challenge the divine.  The excessive pride that Pentheus holds, the irrational hatred that drives him to want to best Dionysus and eradicate any trace of him from Thebes, is the exact opposite of the Chorus.  They operate as the other choice that humans can embrace when struggling to figure out how they shall live and what they shall do.  Whereas Pentheus wishes to assume a type of totality that is equivalent to the divine, the Chorus operates as serving devotees, willing to extol the glory and virtue of their chosen divine.  This becomes a stark contrast to the humans like Pentheus who voice skepticism and doubt as opposed to faith and a sense of subservience to that which is more encompassing.