To what extent does the supernatural foresee what is already within a character in Shakespeare's Macbeth and Sophocles' Oedipus Tyrannus?

In Shakespeare's Macbeth, the supernatural is primarily represented by the Three Witches. Early in the play, they greet Macbeth with two titles which he does not yet hold. The last of these titles is that of king: "All hail, Macbeth, thou shalt be king hereafter!" Given this comment, it seems reasonable to conclude that these women foresee that Macbeth is ambitious enough to become king, even if it means participating in the murder...

In Shakespeare's Macbeth, the supernatural is primarily represented by the Three Witches. Early in the play, they greet Macbeth with two titles which he does not yet hold. The last of these titles is that of king: "All hail, Macbeth, thou shalt be king hereafter!" Given this comment, it seems reasonable to conclude that these women foresee that Macbeth is ambitious enough to become king, even if it means participating in the murder of the king, who also happens to be a relative of his and a guest in his house when the killing takes place. The Three Witches may also foresee that Macbeth's wife is also ambitious enough to encourage Macbeth to kill King Duncan. 

As for Oedipus in Sophocles' earlier play, the supernatural in that play is primarily represented by Apollo, a god connected with wisdom and with the famous oracle at Delphi (also called Pytho in the play). It is difficult to say, though, what character trait Oedipus has which leads him to kill his father and marry his mother, as Apollo's oracle predicted. Indeed, this is a matter of great controversy. Some have thought that Oedipus had a bad temper, although other scholars have denied this.

What cannot be denied, though, is that Oedipus was a man who wanted to discover the truth, no matter what the cost. Perhaps this is what Apollo foresaw in Oedipus. It was Oedipus' search for the truth about his parents that led him to leave the house of Polybus and Merope and travel to Delphi. During that journey, he had a violent encounter with Laius, whom he killed, but did not realize was his father.

It was also Oedipus' search for the truth that led to him discovering that he had, in fact, killed his father and married his mother. So, perhaps Apollo foresaw that Oedipus was the sort of person who would seek the truth even if it destroyed him, his father Laius, and his mother Jocasta. 

      With all these indications of the truth
      here in my grasp, I cannot end this now.
      I must reveal the details of my birth. (Johnston translation)