In 'Macbeth', Shakespeare presents the idea of the supernatural through the witches prophecies - as Shakespeare illustrates the witches as a subversive force of whom control and manipulate Macbeth and Lady Macbeth, as they influence their ambitions through this didactic play's central theme of ambition and regicide. Moreover, the use of the supernatural by Shakespeare represents a warning to the audience of the evil and sin these forces entail, as this theme reaffirms King James the first's warning (to please him) of witches and their threat to the status-quo (in his book: Daemonologie).
Firstly, Shakespeare uses the witches and their prophecies as a construct to represent how engaging with the supernatural will lead to your demise, as their prophecies seem to foreshadow the entire play - illustrating their control over Macbeth and Lady Macbeth and thus linking their prophesies to their demise. This is illustrated through the atmospheric imagery in the syndetic listing: "in thunder, lighting, or in rain". Firstly, the syndetic listing used creates a cumulative force and depth to the imagery, dramatizing the statement "when shall we meet again" as pace increases. As this pace prolongs the tension of the text, we could argue that this emphasises the idea of "thunder", which we can argue is emblematic of Lady Macbeth's aggressive behaviour through her adamant belief of subterfuge to commit regicide. This may be true as the sound "thunder" connotes may resemble Lady Macbeth's moral manipulation via her speech - "chastise with the valour of [her] tounge". Moreover, the rarity "lighting" connotes (being struck by "lightning") may be a metaphor for the oddity of regicide. Therefore, perhaps Shakespeare is suggesting that the witches are an influential force through the effect the supernatural seemingly has on the play, especially as this prophecy foreshadows the entire play, making it thus seem as if the witches are manipulative through the total control that this idea suggests they have; moreover, the melancholic pathetic fallacy indicative of the noun "rain" conveys them as a perfidious force, as it reflects their evil and immorality. Therefore, through this, perhaps Shakespeare is conveying that the ambition rooted in their prophecies is ("shall be king hereafter") is erroneous, as if the general ambiguity of their prophecies ("fair is foul and foul is fair") leads to Macbeth + Lady Macbeth's ambitions being under false pretences, thus foreshadowing their eventual demise at the end of Act 5 (as if their prophecies are the collective hamartia of the two).
Moreover, Shakespeare uses the idea of the supernatural as a construct to represent the threat they are to the traditional values of the mainly Gentry-based audience, as the tyranny they unleash contrasts with the return to classical values in Jacobean society (based in the Medieval times) via the rise of the gentry. This is exemplified through Lady Macbeth, and how her ambition of being Queen ignites a sense of aggressiveness within her, which acts as an inversion of the patriarchal society at the time and thus the a-typical nature of the supernatural. This is conveyed through her imperative demand to Macbeth, to "look like the innocent flower, but be the serpent under't". The use of the imperative verbs "look" and "be" convey her power within their relationship, as she seems to be dictating Macbeth's behaviours. This therefore emphasises her moral indecency indicative of the word "serpent", which has connotations with sinful biblical imagery and Eve's sinful influence over Adam at the Garden of Eden. Moreover, this reflects the tactical and immoral influence of Lady Macbeth as this juxtaposes the idea of being "innocent". Thus, clearly then, this illustrates Shakespeare's efforts to personify the supernatural as a destabalising force on society, as this juxtaposition reflects the duplicitous nature of her demands: to appear "innocent", but to be sinful. Hence, this reflects her intelligence through the acceptance of subterfuge being a prerequisite in regicide, as well as brute force. Overall, this thus illustrates Lady Macbeth as being the 'fourth witch', as her manipulative behaviours overlap with the three witches. Therefore, this elucidates Shakespeare's intentions to overlap matriarchal values with sin and evil via the supernatural, as they're seen as unnatural by the audience.
Additionally, Shakespeare uses Macbeth as a symbol of the futile nature of regicide, as Shakespeare uses the idea of the supernatural serving as Macbeth's hamartia through his ambitions being all for nothing at the end. This is illustrated, at first, through how Macbeth acknowledges the nature of his "ambition[s]": "vaulting ambitions with o'erleaps itself". The use of the verb "o'erleaps" personifies Macbeth's ambitions (with movement), conveying how Macbeth's actions are selfish as his "ambition" (regicide) seems to overleap itself, as if it leaps over the obstacles set by Macbeth. This therefore conveys the sheer power of the supernatural as a disturbing force as Macbeth's desire to be king juxtaposes the idea in Act 1, Scene 1, of him being a "minion" to the King, who is endowed in servitude to the monarch (especially as his name links with the Divine Right of Kings through its literal meaning of "life" and God). Overall, it's clear then that Shakespeare conveys the supernatural as an immoral influence through Macbeth's transition from a servant to the king through his success in-battle, to how he's corrupted by his selfish desires - indicating his wavering moral compass.
Lastly, Macbeth's transition as a by-product of the supernatural is reaffirmed through Shakespeare's deliberate efforts to divide the audience between those empathetic and those who detest Macbeth's actions. This is indicated by the sematic field of temporary and short-lasting imagery with the noun "candle" and the phrase "poor-player", representing Macbeth's blasphemy against the ubiquitous Jacobean Christian idea of God's plan (as this creates the idea of Macbeth's rejection of life's worth through nihilism). Thus, as this juxtaposes his original "valour" - his bravery - we may argue that Shakespeare uses the witches and the supernatural to separate Macbeth from God (especially as he can't say grace, a Christian tradition: "wherefore could I not pronounce Amen"). Hence, whilst some may be empathetic towards Macbeth's 'fall from grace' as a soldier, others may find his language shocking (thus representing the aganorsis as part of Macbeth symbolising an Aristotelian tragic hero). Overall, this portrays how Shakespeare uses the witches to showcase how your "black" and "deep" desires will ultimately drag you along the path of hell through sin.
In conclusion, Shakespeare uses the supernatural as a destabilising force within society as the witches are portrayed as the underlying hamartia of Macbeth and Lady Macbeth.