What does Genesis 12:2 mean?

In the previous verse, God began His seemingly out-of-the-blue contact with Abram. God commanded Abram to go away from his country, his people, and his father's household and to go to an unspecified land God would show him.

Now God begins a series of huge and powerful promises to Abram, which will accompany this leaving behind of everything he knows. God vows to make Abram—through his descendants—a great nation. God will bless Abram. God will make Abram's name great. God will make Abram a blessing.

These promises were the very things the great kings and leaders of Abram's time would have longed for themselves. We're told nothing of Abram's personal ambitions, but it seems likely these promises would have surpassed his wildest expectations for his life. Keep in mind, when these messages came to Abram, he was a childless 75-year old man living in his father's household!

Even so, the next verse contains yet more promises from God.