In Macbeth, Macbeth is certainly influenced by the witches and their prophesies to the point of continuing on a destructive path.
Banquo and Macbeth both faced the witches at the same time and both hear the same prophesy:Macbeth "shalt be king hereafter" (I.iii.50) and Banquo "shalt get kings though thou be none. "(67)Both are intrigued by the possibilities and both recognize the inherent danger as Banquo points out that "the instruments of darkness tell us truths....to betray's"(125) and Macbeth knows that "this supernatural soliciting Cannot be ill; cannot be good."(131) Banquo however, does not act on the information.
Immediately, Macbeth begins scheming and Lady Macbeth is prepared to go to any length, even to "unsex" herself to ensure the prophesy. As the murders become easier for Macbeth and there appears to be no stopping him, he returns to the witches for confirmation of his future.
The witches recognize Macbeth as "a wayward son, Spiteful and wrathful" (III.v.11) and Hectate, the head witch warns the weird sisters of him. Hectate also knows how easily led Macbeth is and intends to take full advantage as he "shall spurn fate, scorn death and bear his hopes 'bove wisdom.."(29-30). It is clear from Hectate's ramblings that Macbeth will secure his own fate as he is unable to control himself now that his "vaulting ambition" (I.vii.27)has unleash'd itself.
The ability of the witches to manoever Macbeth reveals his evil nature but they have no control over the course of events, even if it can be suggested that they can predict future occurrences. It is Macbeth's own actions, beliefs and overwhelming desires that catapult him to a position where it becomes evident that his interpretation of Great Birnam Wood advancing on him and his misunderstanding of MacDuff's birth as "from his mother's womb untimely ripped" (V.viii.15) seal his fate.
It can therefore be argued that the witches represent the temptation that everyone faces. Having the strength of character to do what is right is present in many of us but unfortunately there are others , even in the present day, more like Macbeth who allow the "juggling fiends" (V.viii.19)to influence their actions and who "lay on" (33) despite the harm they may cause to themselves and others. .
In a sense, they were temptations we all face. They showed Macbeth the promise of something amazing and he never questioned the source of this information, letting himself get caught in lies and half-truths.