Wow. Honestly...there's just so much in the call of Abraham that I feel overwhelmed trying to write a short comment on it today. A few questions?
Why do you supose Abe and Sarai followed? I mean was it their amazing uncanny faith? Wait, I know they had faith, and we rightly celebrate that faith at the start of this chapter. Sarai and Abe went to the land that God sent them to without a backup plan or clear direction--sounds like faith to me. But were there additional motivators? Didn't Sarai and Abe have a frustration? Didn't they long for something that hadn't come about? See: Gen 11:30.
And...what had God promised them?
What happens when sincere faith mixes with human desires and insecurities?
What do we do with Abe and his behavior in Egypt and elsewhere? Abe misrepresents his relationship with his wife. (That's a crazy understatment...the bible is filled with chuavanism and so was the world in which it was written.) I feel like Abe should be carrying a cane and wearing a fuzzy purple hat the way he tries to pimp out his poor wife.
Can we love without hooks, can our motivations be pure to the core? Abraham does reflect amazing faith. But we shouldn't ignore the fact that he does a lot of stupid shit as well. Is there a way to rise above a selfish faith? Maybe we could discus that question? Consider starting here.