In what point of view is Paradise Lost written?
It depends on which book of the epic poem you are discussing. Here is a brief review of what "point of view" means in literature:
In literature, physical point of view has to do with the position in time and space from which a writer approaches, views, and describes his or her material. Mental point of view involves an author’s feeling and attitude toward his or her subject. Personal point of view concerns the relation through which a writer narrates or discusses a subject, whether first, second, or third person. If personal point of view is used and the writer assumes the point of view of a character, the author is writing in the first person. If the author takes the point of view of an observing character, the author is writing in the second person. If an impersonal point of view is taken, the author detaches himself completely and is an omniscient author, or third person. Sometimes authors employ several points of view in the same work. (enotes Guide to Literary Terms)
So, in Paradise Lost, Milton could be telling the story of the poem from his point of view, or from the point of view of another person, or as an omniscient narrator. Also, Milton could address things in the poem directly to the reader. In this long poem Milton uses all the possible points of view.
In Book I we hear the the poet's voice, hoping "That, to the height of this great argument,/I may assert Eternal Providence,/And justify the ways of God to men" (Book I, lines 24-26) The poet speaks as himself, the real-life person John Milton, and addresses his audience directly. Book II begins with a description of Satan, and, in the form of an omniscient narrator, Milton allows us to hear Satan speaking. A similar situation is in Book III, wherein God the Father is shown in his heaven, and allowed, too, to speak in his own voice. This carries Milton's narrative omniscience (and invention) to its furthest degree.
So much of this poem is told through the eyes of the magnificent fallen angel, Satan, and Book IV shows us Paradise through his eyes. Book V continues the human perspective begun in the former book, and has both Eve and Adam speaking. In book VI, VII, and VIII, the angel Raphael speaks to Adam, telling of events which happened to Satan and the other fallen angels and to the Messiah (Jesus). Satan comes back in Book IX, and he sets in motion the story of Eve and the apple, and the fall from grace. Various supernatural beings, and God himself, speak in Book X, and Jesus speaks directly to God in Book XI. The archangel Michael speaks to Adam, and the poem ends with Eve and Adam leaving Paradise.
The answer to the "point of view" question is, really, that this epic is written from Milton's point of view. A fervent and devout Puritan, Milton wanted a Christian epic poem on the same scale as the pagan ones (the Iliad, the Odyssey, and the Aeneid). So, while using the Biblical stories, and Christian tradition, as his source material, Milton was choosing to "justify" his Christian worldview with a creation/foundation poem which fit his theology. While he writes well in others' voices (he is particularly sympathetic and persuasive as Satan) the point of view of the overall poem is Milton's own.