Ion: But I must scold Apollo.
What is the matter with him?
Ravishing girls and then deserting them!
Sneakily making babies, then leaving them to die!
That’s not you, Apollo, surely!
You have the power, so follow virtue.
Wicked men the gods punish,
so how can you yourselves flout the laws
you’ve made for mortal man?
If the day ever comes
(I know the notion is absurd)
when you gods must pay the price to human beings
for all your rapings and your whorings,
your and Poseidon, yes and Zeus himself the king of heaven,
will bankrupt every temple to meet the bill.
To chase your fancies without thought is wrong.
One simply can’t go on blaming human beings
for copying the glorious conduct of the gods:
blame the setters of example (119-120).
Old Man: It’s a fine thing to be law-abiding when things go well
but when it comes to enemies the law’s an obstacle (140).
Ion: One cannot sidestep fate (153).
Cruesa: Dire indeed was our destiny then
And dire out destiny to follow:
Flung to and fro, baubles of fate
Sometimes fair, sometimes foul.
But winds veer.
May a fair wind stay—
A calm after storm, my child.
We have suffered enough (157).
Whole Chorus: Those whom misfortune undermines
Should reverence the gods and take courage.
The virtuous in the end will win,
The wicked, by their nature, not:
Because of sin (161).
In his short introduction to the play in the Signet Classic Euripides: Ten Plays edition, Paul Roche refers to Ion as a tragicomedy, but I think it is in fact a romance. It seems to have the classic characteristics of a romance—tragic potential averted because the characters have redeeming qualities, a happy ending with a family created/restored, and so on. But because this is a Euripides play we don’t have a straightforward romance—Euripides loved to tweak things just enough to make them problematic. In Ion there is an intervention of fate in the plot, but the characters are nearly destroyed by the very people they seek: Cruesa nearly poisons her long lost son, and Ion nearly murders his mother for revenge. I think for Euripides this is the more interesting role of fate than Apollo ordering Hermes to deliver baby Ion to the temple at Delphi. Generally in romances there is some kind of external force keeping the lovers (or in this case mother and son) away from one another, but in Ion the characters nearly destroy the very things they seek in an attempt to get the objects of their desire. Specifically, to ensure a place for her son, Cruesa nearly poisons Ion, who is her son though neither of them know it yet; and Ion nearly murders his mother in order to try and secure a place for himself in his family.
The other thing Ion does, which is characteristic of Euripides is presenting the gods in a fairly poor light—especially Apollo. Apollo had raped Cruesa long before the play and she had his child and abandoned it out of shame. To the best of her knowledge, Apollo had let the child be eaten by birds and other animals, which he let her think for some 18 years. His plan to reunite the family is a somewhat bizarre one, which requires some tricky oracular prophecies—prophecies which nearly lead to Cruesa and Ion murdering one another. Then at the end of the play Apollo doesn’t even have the courage to show up himself and justify his actions, but sends Pallas Athena to come and explain his plans.
Way more than Aeschylus and Sophocles, Euripides often made the gods comically human, with the same kinds of desires and incompetencies as the human beings they are supposedly superior to. Although Greek drama often uses the gods/curses as catalysts for dramatic action Euripides is often the only playwright (at least of these three) who is willing to bluntly call the gods to task for meddling in human affairs.