The expressions "begotten" and "Son" were borrowed Hebrewisms from the Patriarchs and Davidic dynasty psalms, such as Psalm 2, where God tells David (and each member of his house) that anyone who would sit on his throne in that dynasty would become a "son" or an "incarnation" of God to the people of Israel. This type of terminology was used by other cultures such as the Greek and Roman rulers who would in later centuries call themselves "son of god," or "begotten" of a deity, not meaning they were a child but an incarnation of their own heathen and pagan gods on earth. The New Testament writers of the gospel used these expressions as they struggled to explain finding God in Jesus since they were Jews who at the same time believed in the unbreakable centrality of the Shema. Thus they referred to Jesus as God in those terms--an "incarnation"--using those particular Hebrewisms since Judaism didn't have the word "incarnation" as it was Latin and they were as of yet unfamiliar with the tongue and the Pagan religion from which it originated.
As to the make up of the states, that is more of a religious question belonging to denominational makeup and division. Most in Christianity believe Jesus was fully human and fully divine, but since God is Ineffable, how this works is thus beyond comprehension in most of these religious theologies.
According to the Catechism of the Catholic Church, the Scripture text at Genesis 1:26-27 wherein one finds the words "let us make" is not just about Jesus but has long been held by all branches of mainstream Christianity as pointing to the likely involvement of each person of the Trinity, including the Holy Spirit and the Father, in creation.--CCC 307, 1942, 2402.
As to the "antichrist," this is generally understood in Scripture and theology as a psuedo-messianic figure or deception, usually one that is expected to appear before the eschatological conclusion to history.