Macbeth would not have followed the same path if the witches had not been involved.
He had very strong misgivings about killing King Duncan anyway.
He didn't really like the idea of murdering the King, especially when he was his host and, as he says, he "should against his murderer shut the door, not bear the knife myself." (Act 1, Scene 7) In Macbeth's soliloquy in which he uses the simile that "his virtues will plead like angels, trumpet-tongued, against the deep damnation of his taking off," (ibid.) he gives several reasons why it would be a bad idea to commit the murder.
His wife keeps goading him, but by herself she probably could not convince him that it would be easy and that no one would suspect them. He needed the assurances of the witches with their supernatural intelligence to make him feel that he could get away with the crime and that he had to do it anyway because it was inevitable, it was predestined. Shakespeare must have realized that he needed something stronger than Lady Macbeth's haranguing to motivate Macbeth. She lacks her husband's foresight. She can't see what might happen in the future--but the wiitches can!
Macbeth had one opportunity to kill Duncan. That was during the one night when Duncan would be staying in Macbeth's castle. If he didn't do the deed that night, he might never have a chance to do it later. He had to dispose of Duncan and do something about Duncan's two sons, Malcolm and Donalbain. He had all three in his castle on that one night. Evidently he didn't plan to kill the sons, but he had to do something about them. He could make it look as if they were responsible for the murder of their father, but only if they were on the premises on the night of the murder. So if Macbeth vacillated on that one night, the whole story would have been different. He might have had to wait for years for another opportunity, and Duncan was very unlikely to be staying at Dunsinane again. He had never been there before, as is shown in the scene where he first arrives and says, "This castle has a pleasant seat. The air nimbly and sweetly recommends itself unto our gentle senses." (Act 1, Scene 6.) Obviously he has never seen the place before.
In the opening of Act 1, Scene 7, Macbeth gives many reasons why he shouldn't commit the murder and why he doesn't want to commit the murder. Without the witches, Lady Macbeth would have a hard task overcoming all Macbeth's misgivings. He knows intuitively that he would be exposing himself to be murdered if he became king. "...we but teach bloody instructions, which, being taught, return to plague the inventor. This even-handed justice commends th' ingredients of our poisoned chalice to our own lips."
The strongest evidence that Macbeth would not have killed Duncan without the intervention of the three witches is in his own character. He doesn't want to commit treasor. He doesn't want to commit murder. He knows it could only lead to all kinds of trouble--which it does. He could perhaps pacify his wife by telling her he will do the deed, but not that night, maybe later. There is only that narrow window of opportunity. She can't do the deed herself, although she thinks about it. She says, "Had he not resembled my father as he slept, I had done 't." (Act 2, Scene 2)
what would be the three points ?
No, he would not have followed the same path if it werent for the witches.
He would not have killed king Duncan if it werent for the three witches.
He would not have killed Banquo if it werent for the three witches.
He would not have desired to be King if it werent for the three witches.....or to be the Thane of Glamis or Cowdor