'Sunshine of Saint Eulalie' was she called; for that was the sunshine
Which, as the farmers believed, would load their orchards with apples;
She, too, would bring to her husband's house delight and abundance,
Filling it with love and the ruddy faces of children. (144-147)
Right from her introduction, we see that Evangeline is primed for love—and marriage. She's the ideal love interest in the eyes of the villagers and, while that might be offensive to our modern ideals (she could probably be a lot more than just an ideal housewife, after all), this passage introduces the possibility of domestic bliss that Evangeline represents.
Little she dreamed that below, among the trees of the orchard,
Waited her lover and watched for the gleam of her lamp and her shadow. (373-374)
This is Evangeline and Gabriel's Say Anything moment. They're about to get married the very next day, but Gabriel can't resist trying to steal one last glimpse of her by standing outside her window. That's some love right there, gang.
Merrily, merrily whirled the wheels of the dizzying dances
Under the orchard-trees and down the path to the meadows;
Old folk and young together, and children mingled among them. (415-417)
Love is not just something that's enjoyed by the happy couple. The whole village has a stake in the love between Evangeline and Gabriel. They all come together to celebrate their wedding in a communal celebration of love's value.
'Gabriel! be of good cheer! for if we love one another
Nothing, in truth, can harm us, whatever mischances may happen!' (559-560)
Well… nothing except for wild pigeon fever that is, which is what apparently does Gabriel in at the end of the poem. We take Evangeline's point, though: love conquers all. Even though the doomed couple never quite make it work, the power of their love is evident in the way it sustains Evangeline on her search.