The "PARADISE LOST" by John Milton is an epic poem that tells the biblical story of the fall from grace of Adam and Eve (and, by extension, all humanity) with the main characters being God, Lucifer (Satan), Adam, and Eve. The story is an explanation of Adam and Eve with details of how they came to be created and how they came to lose their place in the Garden of Eden, commonly known as Paradise. This is a similar story to what is found in the beginning of Genesis in the Christian bible expanded by Milton into a very long, detailed, narrative poem including the story of the origin of Satan.
In the poem, there exists numerous discrepancies between what Satan says to his followers in Book I and what he reveals to us in his soliloquy in Book IV. Among these include his bid to rally his followers in a victorious war against the administration in heaven by God who happens to be the ruler of the kingdom in which he is subject to. In chapter 1, the Lucifer is optimistic that they will be victorious in the battle and so he takes no chances in leading a campaign against God in which he denounces him as his ruler. According to him, God is a liar and a dictator who is talking advantage of them by taking advantage of their ignorance and not letting them know the truth regarding various aspects about the kingdom.
This He does to continue having them as his subjects. However, in his soliloquy in Book IV, the Lucifer is seen as regretting his decision that he made a mistake leading this battle against his ruler as he doesn't seem to win at any point in time. He is considering God as not having had ill intentions as claimed in Book 1 and that he had not denied them knowledge to take advantage of them but He meant every bit of good for them. This is a contrast as compared to the claims the Lucifer is making about God in book 1.
At the same time, in book 1, the Lucifer sees his battle against God as having led man astray for all the wrong reasons, according to him, he is responsible for that and therefore he feels that this should not have happened. He is merciful to the inhabitants of the earth that they will have to pay a heavy price for what they did not sow because he is on a mission to get more followers and therefore this according to him is not a good thing to do. In the first chapter however, the Lucifer is seen claiming that man should join him to fight the ill intentions that God had to rule over them forever.
This illustrates a state of divergence in that he is now considering the human position as wrongly and ill influenced by him something that he should not have done. His claims are that he misguided the human race innocently in disobeying God in book 4 unlike his earlier assertions in book 1 that it was just for man to wage war against their ruler in heaven who is God. These are among the various discrepancies between what Satan says to his followers in Book I and what he reveals to us in his soliloquy in Book IV.