Constancy
"Constancy" is what Longfellow lauded when he first heard this story from Hawthorne's friend. Indeed, Evangeline is nothing if not constant. She waits for years upon years, wandering the continent and growing old; she never falls in love with anyone else and endures the utmost in sorrow. The fact that she continues to praise God and do His good works while mourning for her lost love and never losing hope that she will be reunited with him is what Longfellow considers so admirable. Of course, modern day readers may scoff at this and simply wonder why Evangeline and presumably Gabriel couldn't just fall in love with someone new and live a happy life, but the text holds this constancy up as an example to be admired and honored. This is true love sustained by great faith.
Fate and God
The Acadians do not seem to be in control of their own destinies. They are weak individuals, buffeted by the winds of fate as symbolized by the British. They are thrown out of their homeland, separated from their families and friends, and scattered far and wide across the British colonies. They cannot resist or refuse; their fate is out of their hands. As Longfellow sees it, God is still in charge, however. God knows what is in store for the Acadians and he will bless them even as they suffer. His hand guides them and He will assure that they are rewarded in heaven if not eventually on Earth.
Suffering
Suffering is one of the most pervasive themes of the text. All of the Acadians suffer when they are rounded up, their homes burned, and their families scattered across the the wilds of North America. They are exiled, their lives bereft of meaning and freedom, sent amongst people they do not know all the while mourning their lost families and communities. Evangeline's quest to find her beloved Gabriel, compounded by the suffering incurred when she must watch her father die of shock, exemplifies the suffering of all the Acadians. Suffering is to be conceived of as part of God's plan, however, and enduring that suffering without complaint is a testament to one's virtue.
Utopia
One of the reasons why the British expulsion of the Acadians is so tragic is because what they had in their homeland was nothing short of utopian. There the divisions between rich and poor were negligible; the poor had everything they needed and the rich were not avaricious. Abundant and fruitful land was shared by all. The natural landscape was beautiful and serene, the houses comfortable and stout. Women were lovely, men were wise. Religion was benevolent, children were guileless. There was a harmony among all people of all particulars. Thus, the expulsion into the harsh world outside Acadia was utterly tragic because it destroyed a veritable heaven on earth.
Home
The Acadians had a perfect home (see above) but were forced out of it against their will. They spend months and years looking for a new home—a place where they can feel free, secure, and in a community of their own. Evangeline's mournful wanderings are a testament to how important a home actually is, for she is not just bereft of Gabriel but also the security, stability, and comfort that her future home with him promised. The importance of home also becomes clear when readers encounter Basil again, for he has created a new home amidst the like-minded people of Louisiana and other exiles from Acadia. He is prosperous, peaceful, and happy; he is a symbol of how having a home and having roots benefits people.
The Past
The characters in this poem are mired in the past. Once expelled they mourn for their homeland for a near-interminable amount of time. Evangeline and Gabriel mourn for each other for their whole lives, never able to move on and start a new life. The past has a strong hold on the minds of the Acadians because it was idyllic, peaceful, and harmonious; their new life is chaotic, strange, and sad. The past is a refuge of sorts; at minimum, an emotional one.
