In Ken Follet's Fall of Giants the main idea is quite simple to grasp: those who suffer and need have to figure out how to survive. As a result, they end up at the top of their game in a dynamic society because they can handle change and chaos. Those who blindly continue to follow the mandates and tenets of the past without wavering will end up becoming extinct.
This being said, the motif of social injustice is used in the book as a way to illustrate the extent to which the survival mechanisms of the poor render them more able to think and use logic whereas the overfed rich merely live away their riches...until the day it all ends and the giants fall. One prime example occurs at the very beginning of the novel where Follet exposes the sad and gritty world of miners.Let's focus particularly on the courageous Ethel, her disgraced romance with Fitz, and how class dictated respect in England.
The miners, whose work is taxed by the upper classes, can hardly put any food on their tables. So sad is their situation that even the rats at the bottom of the mines eat their food if it is not covered properly. Contrastingly, the "world upstairs", where the Earl Fitzherbert celebrated, denoted an over-pouring of food of colossal dimensions, showing the gluttony and opulence of society's "giants".
The menu began with hors d’oeuvres Russes, . . . little blinis with caviar and cream, triangles of toast and smoked fish, crackers with soused herring, all washed down with the Perrier-Jouët 1892 Champagne.
In chapter two, we learn that the miners are considered less than nothing by society because the new safety laws that were required to be followed in England for all workers were not applied, causing for a mining explosion to occur. This was the beginning of what would be an endless fight for the rights of the miners throughout the novel. However, it is notable that these "bottom feeders" whose work make the rich richer were not even considered worthy of protection.
In chapter 4 we find that the families of these miners were forcibly evicted from their homes in Aberowen. The King does not respond to their requests despite having made a "show" appearance of bereavement after the explosion. The poor became even more destitute.
In chapter 14 we find Ethel working very hard to earn her keep although the child that she is pregnant with belongs to Fitz, who is an aristocrat, is married, and clearly tells her that her child is not important enough. While Fitz ensures that Bea gets all the commodities proper of her rank, he had no choice but to provide Ethel with a boarding house for her to earn a living. It is clear that she cannot, for she tells Billy that she is in need. This is how Fitz identity's is discovered.
Chapter 36 shows how Billy, due to conditions that denote his lack of power, but still show his character, is unjustly brought to court Marshall for revealing military secrets and sent to a prison in London.
The role of religion in the novel is not as strong as the role of politics and power. Yet, all religious tenets are questioned and challenged in the behaviors of those who go against the establishment and fight to make a difference. Ethel's out of wedlock pregnancy, the broken marriage vows and war clearly go against established religion and challenge its spiritual concepts.