It's evident that Delia's faith sustains her through many ordeals in her marriage; the text documents this clearly. Let's take a look at the text, and then you can decide whether Delia would have survived without her faith.

After years of physical and verbal abuse, Delia finally stands up to Sykes. The text tells us that it is her faith that sustains her.

Somehow, before sleep came, she found herself saying aloud: "Oh well, whatever goes over the Devil's back, is got to come under his belly. Sometime or ruther, Sykes, like everybody else, is gointer reap his sowing."

Delia's words recall similar ones from a Bible verse: "Do not be deceived: God cannot be mocked. A man reaps what he sows." (Galatians 6:7). Because of her faith, Delia is able to exhibit a "triumphant indifference" to anything Sykes says or does. Even after Sykes parades his mistress Bertha around town, Delia clings to her faith in God:

Delia's work-worn knees crawled over the earth in Gethsemane and up the rocks of Calvary many, many times during these months.

Later, when Sykes brings back a rattlesnake to terrorize Delia and to facilitate her departure from their home, Delia continues to rely on her faith for strength.

She stayed to the night service—"love feast"—which was very warm and full of spirit. In the emotional winds her domestic trials were borne far and wide so that she sang as she drove homeward.

From the above, it can be argued that Delia's faith definitely sustained her in times of extreme physical and mental suffering.