In his first epistle, Peter quotes Hosea 1.9-10 suggesting that the fulfilment of the Children of Israel being as the sand of the sea is found in the Gentile inclusion. Hosea hints at this and the New Testament confirms it in uncertain terms.
1 Peter 2 speaks of the disobedient who stumble - an indication of apostasy. The Holy Nation is now comprised of people who formerly were not a people but are now the people of God (echoing Hosea).
Theological Modernists and the academy argue that Isaiah was written by two different authors. Chapters 1-39 were written by Isaiah ben-Amos - the Isaiah we all know. Chapters 40-66 were written by another prophet in the exile (the so-called Deutero-Isaiah) who often tries to mimic the style of Isaiah and yet due to the seeming predictive prophecy in those chapters, it could not be the same person - or so it is argued. The naming of Cyrus in chapters 44-45 comes into play as the idea that Isaiah ben-Amos in the 8th century BC could name a future king of the 6th century is deemed impossible. Therefore they argue the second portion of the book was composed by a prophet in the exile period who knew Cyrus by name. And yet because he pretended to place himself in the past and predict the name of the king, he would in fact be a liar. This is not an issue for modernist theologians. This is because these theologians and scholars are unbelievers who reject the notion of revelation. The Bible for them is a series of moral tales and traditions. God may speak through the words but there is nothing unique about the Scriptures. For them, God is just as likely to speak through the writings of another religion or through inspirational figures of our own day.
