I agree with other editors in stating that the cultural function of the Gothic movement was perhaps to reflect the exciting but also terrifying scientific advances that were occurring - but also - and perhaps essentially - to highlight the extent to which science had not been able to provide a rational explanation for everything. Gothic literature thus focussed on the supernatural, dreams, visions, omens and madness - things which had not yet been explained.
One cultural function of the gothic narrative is for exploration of the human soul. To illustrate this function, one may examine the works of many a gothic author. In the twentieth century, one gothic author, Flannery O'Connor, has certainly provided readers with exploration into the attainment of grace through the gothic. In her short story "A Good Man is Hard to Find," for instance, the grandmother undergoes a personal experience that is significantly different from the norm; it is a situation where there is redemptive grace in a fallen world. For, the grandmother's recognition that, like the Misfit--the evil messenger from God--she, too, is a sinner is what redeems her. Critic Patrick Galloway writes,
What at first seem senseless deaths become powerful representations of the swift justice of God; the self-deluded, prideful characters that receive the unbearable revelation of their own shallow selves are being impaled upon the holy icicle of grace, even if they are too stupid or lost to understand the great boon God is providing them.
According to Baker and Womak (2002), the Gothic period novel is a reflective literary movement that came as a reaction to the late Victorian reign period, and also occurred as a result of the myriad of discoveries taking place in the mid to late nineteenth century.
The onset of the Industral Revolution and the impact it caused on 19th century England prompted society to question everything that they had known: The middle classes began to outrun the aristocrat classes, religion became diversified as a result of Darwin's findings, human psychology began to be regarded as a field of deep study, and life, as people knew it, changed immensely.
If we take Gothic literature and its top three contenders: Frankenstein, Jekyll and Hyde, and Dracula, we can see how each of these novels question everything we had ever taken for granted: The nature of humanity, the capability of transformation, the origin of radical changes, and life in itself as a mysterious period of existence. Death is questioned, nature is questioned, and the unraveling of man's inner demons (Freud's "basic Id") are consistently mentioned.
In summary, the Gothic novel is basically a revival of the last of the great Gothic novels which occurred with Maturin's Melmoth the Wanderer, and is mainly a style that is applied to study the changing times of the Victorian era, and the many questions (most without answer) were adjoined to a method of literary presentation that involved mystery, the touch of the supernatural, the necessity for fear, and the inevitability of life, death, and fate.