Christ Is Israel, the Seed of Abraham

Who is the seed of Abraham? Many have tried to trace their DNA or lineage to Abraham so that they might be called the people or God. Today much fighting over land in Palestine exists because of people claiming to be the blood descendants of Abraham. Yet, by and large, they reject Jesus Christ. Others in America such as Hebrew Israelites also claim to be the blood descendants of Abraham. Another minor group, called Israel only claim the bloodline descendants from Abraham, or even from Adam, Cain and Abel are Israel or the fathers of Israel. Who are the real sons of Abraham? Who is Israel?