Let's break down the text to examine each reference in Act 2, scene 3. First of all, if you knock at the gate of hell, we can pretty much assume your character has been sinful, so, the question is, has Macbeth committed any of the following sins? For your analysis:
First person who knocks on the door: "Here's a farmer that hanged himself on th’ expectation of plenty..."
How is Macbeth like a farmer? Does Macbeth assume he'll get a fat harvest? Does Macbeth seem like the type that could eventually commit suicide? How do you know?
As you answer these questions, you can pull evidence from scenes in the play that prove yes, there is a parallel.
Second knocker: "...here's an equivocator that could swear in both the scales against either scale, who committed treason enough for God's sake, yet could not equivocate to heaven." If you look up these references (also related to the politics of Guy Fawkes' treason and a Jesuit priest caught in the plot against King James), equivocation comes down to lying. Has Macbeth lied? Has Macbeth committed treason?
The third knocker: "Faith, here's an
English tailor come hither, for stealing out of a French
hose. Come in, tailor; here you may roast your goose..." Is Macbeth at all like a tailor? Has he been stingy? Here's a bit of a stretch to get Macbeth connected with what may be just what it is, a joke about the differences between the English and the French. The English often imitated French fashion and so by not being the same experts as the French, might be more likely to make mistakes. Has Macbeth made any mistakes?
They say there's a grain of truth in all jokes! So, back to your text and see if you can prove that Macbeth has committed any of these sins. Good luck!
The Porter mentions three people, or types of people, who might be knocking at hell's gate: the farmer who hangs himself because his schemes to get rich did not pan out, a liar who tries to talk his way into heaven, and a tailor who cheated his customers. Macbeth is similar to the farmer because like the farmer, he tried to take a shortcut to achieve his goal. Rather than depend on hard work to get ahead, the farmer tried schemes to shorten the process and then when that didn't work, he killed himself. Macbeth tries to shorten the road to royalty by killing Duncan rather than wait to ascend to the throne naturally. In the end, his schemes brought about his death, almost as if he killed himself. Like the liar, Macbeth also tells lies to achieve his goal and to maintain his position. He lies to everyone, even to the murderers who kill Banquo for him. The more lies he tells, the more he has to cover up with even more lies. Like the tailor who cheated customers by not giving them enough cloth, Macbeth cheats the people of Scotland by not giving them a true king. He took the life of their king and put himself in that king's place.