This novel is about PTSD. It's obvious that the moralistic implication of the novel is that although life is incredibly traumatic and frustrating (for everyone, but for some in particular), each person is required to seek medical or psychiatric help when they are ill-minded. If not for their self, then for their loved ones.
Look at the cast of the novel. Each character has been harmed by someone's PTSD. Bashkim lives with an abusive father because the family doesn't have the social support of a community, and Sardik is only human. Having been literally hunted by his own government, he is rightly paranoid, but as the title suggests, "We are called to rise," nevertheless.
Did Nate shoot Bashkim's mother because she had a weapon, or was it really, secretly, because she cried to Allah in prayer, triggering Nate's PTSD from the war? Nate's PTSD is another good example of this main theme, and like Sardik, he too beats his wife.
Luis's PTSD lands him in the hospital with a self-inflicted bullet in his brain. Roberta's long history of case-work shows this basic premise to be true: So long as PTSD and paranoia go untreated, the threat is always domestic abuse. Fear makes people violent, and PTSD keeps people perpetually fighting for their life emotionally, so it's the perfect breeding ground for exponential tragedy, where damaged people go on to cause intense suffering for others.
Therefore, the title of the work is its main theme. We are called to rise above the tragedy and damage of our past—but we don't have to do it alone. Luis finds emotional health with a therapist, and he ends up being a tool for healing instead of for causing more pain. Bashkim has a shot at a good life with Luis because Luis had the courage and humility to let people help him deal with his suicidal trauma problems.
