This is the moment when Hamlet listens to his father who has just died. Hamlet's father expresses his anger as you can see from the words "incestuous", "adulterate", "witchcraft", "wicked", "shameful" and "seeming-virtuous" all the adjective used by the ghost express the judgment of a man lived in the Middle Ages who couldn't admit that his former wife could have married his brother.
Therefore it is important in the economy of the text not only because it provides the pretext for storyline to develop, it is also relevant because it conveys the vision of the world, of life and love of a medieval aristocrat. Not only does the extract tell us that religion was the most relevant code of the Middle Ages, but right from the first five lines, an explicit vision of the idea of the woman comes to surface. The king's wife is referred to with series of phrases that convey the role of the woman who couldn't be different from that of a mother or of a pious wife. If you consider substantive like "beast", "witchcraft", "power" and "lust" you may understand why the ghost's judgment is so strict. In addition his words communicate a lot about weltanschaun of the Middle Ages when, all that couldn't be explained in rational terms was considered the effect of witchcraft.
The woman was often associated with the "seducer", a sort of tempting devil to the man.
In the lines following the fifth the ghost's words communicate to the reader an ideal vision of marriage connected with love and dignity, with the idea of a "vow" generally made on the day of the wedding. The lines are also meaningful because they make clear the ideal of loyalty, dignity, honour, love and the given words are the real virtues of the king who, represents God on earth according to the theory of order and degree.
The contrast between appearance and reality is also conveyed by the extract: it can be seen it " most seeming virtuous queen", "in a shape of heaven", " last thou to a radiant angel link'd", and last but not least " prey on garbage".
The idea of death is also there, as it generally happens in most medieval works and in all of Shakespeare's works. Death is generally portrayed as kind of sleep ("sleeping within my awkward"). Appearance and realty are there even when the ghost explains to Hamlet that he had been poisoned. A virtues mind and heart is able to unveil appearance in the moment when Hamlet's father's ghost reveals the mystery "my secure hour thy uncle stole with juice of cursed hebona in a vial". Since now the reader may understand what has really happened, the kind relationship between the king and his son to whom he seems to refers for help in front of the tragedy he was compelled to face "by a brother's hand of life, of crown, of queen". The quotation signs up what the murder has deprived the king of: the values he has been stolen seen the size all of the old king's sense of life. His political power, his existence and the relationship with his wife. The king turns out to be the hero because in the extract he expresses both his human qualities and nature when he is so angry with his wife, at the same time expressing his mind about dignity, life and loyalty. Also his trust in his son is indirectly clear. Who would reveal his intimate secrets if he didn't trust his interlocutor? In conclusion it can be said that the relationship between Hamlet and his father is a close, trusty and affection one.
As far as style the language used by the ghost is too strong and full of energy and expresses too much of human nature for an intelligent reader to believe that it might be to voice of a ghost. The use of alliteration (see for example line 2) of sound "w" conveys the idea of the complained of the ghost. The strange situation that could only come to the light at night, in the dark from a ghost's voice because the knowledge of it might destroy the stability of the new kingdom (hamlet's uncle's one) is well expressed by velar ("gift", "falling") and dental one's ("seduce", "handing hand").
Shakespeare's genius rests in his skill to deal with medieval matters with the Renaissance spirit. As a matter of fact religious seems not to come to the foreground in his extract, rather it reminds in the background to leave the stage to the passions of the body an the heart that are the real themes of the extract.