Now the LORD said to Abram, "Go from your country and your kindred and your father's house to the land that I will show you.
Abram, who later has his name changed by God to Abraham, is called by God to leave his land and to start a new nation (which will eventually become Israel). Through this nation to come, Abraham will be a source of God's blessing on the world, a strong contrast from the fall, curse, and flood of recent chapters.
The blessing will ultimately arrive through Jesus who is of the lineage of Abraham. Abraham is the father of all Jewish people.
God spoke more directly to his people in the past, as he speaks directly to Abram here. This was at least in part because they didn't have the bible - the words and commands of God to the world. By comparing with this book, we can check if modern day "prophets" are really from God. God will not contradict himself by sending a different message in the bible to that of a prophet.