A pagan is, generally speaking from a Christian standpoint, anyone who rejects the authority of the One True God Whom we know personally as Jesus Christ. Saying God required human sacrifice is not entirely correct, for Jesus is God incarnate. Fact: Jesus willingly gave His life that those who believe in Him may attain to life ever after. This is Christianity 101.
Your false idols are very real.
Bringing this back to Genesis: some of my favorite "stories" are there, starting with Abraham and Sarah, and the exploits of their descendants down to Joseph especially, a favorite with many. Joseph saved his people from starvation and explains how the Hebrews ended up in Egypt, first as free peoples, and then as slaves, who Moses was raised up to lead out of bondage, another picture of where all sinners are (in bondage).
Reading through this account, of Moses entreating Pharaoh to let his people go, you may notice that many plagues are brought upon the Egyptians. What you may not know (though it is explicitly stated in the text), is that these plagues were to demonstrate to the Egyptians God's total sovereignty over all the gods and false idols of the most powerful nation in the world. This is seen most clearly at the final plague where God says, “and on all the gods of Egypt I will execute judgment” (Exodus 12:12). Likewise in Numbers 33:4 He states that the plagues were an attack on the gods of Egypt. Pharaoh himself was considered a god by his people. Doing a study on the vast array of these false gods and idols can be very interesting, not losing sight of the fact that God displays His power specifically in order to show that He is the only true God and the only One Who is worthy of worship.