"And I will make of you a great nation, and I will bless you and make your name great, so that you will be a blessing. I will bless those who bless you, and him who dishonors you I will curse, and in you all the families of the earth shall be blessed."
God's radical command (Leave!) came with a promise. It always does.
Consider these grand promises to Abraham:
I will make of you a great nation.
Wow! Quite a promise to a 75-year-old man with no children and a barren wife! But it's just like God, who loves to do the impossible.
Against all odds, the nation of Israel exists today, some 4,000 years later, with a power and influence far beyond its size.
I will bless you.
God richly blessed Abraham the rest of his life. Indeed, Abraham becomes the most important man in all the Old Testament and appears in the New Testament more than any other Old Testament figure. Abraham is the father of the Jews and the greatest example of faith in all the Bible.
And make your name great.
Has that happened? This unknown man, a childless nomad, is known and revered throughout the world today, four millennia later, by Christians, Jews and Muslims. Yes, God made his name great.
When we exalt ourselves (like the people of Babel in Genesis 11, who cry "Let us make a name for ourselves"), then God humbles us. When we humble ourselves, God will exalt us. Every time.
You will be a blessing.
The primary way that Abraham is a blessing is through his descendent, Jesus, who has brought unlimited blessing for all mankind.
I will bless those who bless you.
God so identifies himself with his friend Abraham, that to bless Abraham and his descendants is to bless Abraham's God.
Him who dishonors you I will curse.
To oppose God's chosen people is to oppose God. Satan has fostered anti-Semitism throughout history - Assyrians, Egyptians, Babylonians, Persians, Romans, Europeans in the Middle Ages, Nazi Germany in the 20th century, and others. All of these governments have been toppled. This does not mean that Israel is always right, but the Jews are God's people and we should bless, not dishonor, Israel.
In you all the families of the earth shall be blessed.
The point for Israel was never to focus on themselves but to be a conduit of God's blessing to others, a light to the nations, an instrument to bring God's grace to the entire world.
Tragically, Israel failed at this calling and turned inward, a mistake so many churches repeat today.