Coal-mining as a symbol
Coal-mining is a brutal reality for many Kentucky communities. Often, the mines dry up without warning, as this novel shows. It's a lovely metaphor for the meaninglessness of life, digging up coal for people you'll never meet, sacrificing your health and life to the mines. Then, in a bitter cruel twist, the mine inevitably closes down, leaving a community of hopeless residents. It's a good symbol for the cruelty of fate.
The motif of servanthood
One reason Ruth doesn't take solace in her marriage is that she thinks "men are just men," and that basically, men are just there to boss you around. But then, when Ruth has to get a job, she ends up as a literal servant, the greatest test of her pride she might have imagined.
The gay son as a symbol
Instead of accepting his mother's forbidding attitude toward life, Andrew grows into a free-thinking homosexual. It seems that he realizes that life is even more hopeless than his mother believes, and he abandons belief in God, at least in the very limited way his mother describes it.
The family gun as a burden
Many families have heirlooms, thinks that get passed on to us when our parents die, and in this novel, there is a bastardized inheritance. Andrew receives his father's gun with his mother's indirect suggestion being that he should kill himself. In this metaphor, it seems Andrew has inherited his mother's suicidal depression, symbolized by the loaded gun.
The motif of hypocrisy
An undeniable feature of the novel is its frequent depiction of hypocrisy. Tobias is a would-be minister whose life has devolved into unbridled alcoholism. Ruth is a condemning, judgmental religious fundamentalist who can't see that she's mentally unstable, and her attempt to manipulate and judge her son for his homosexuality are an even more obvious depiction of her hypocritical attitude. Ultimately, the religious zealot is the first traitor to life, and she even goes so far as to give her own son a loaded gun. That's some serious hypocrisy.
