Abram doubts. A lot. Nearly every step of the way, he questions how the promises of God can be so. Sometimes he appeals to external evidence, but not often. Usually it is nothing more than questioning how the promises can be. In chapter 15, God renews the covenant with Abram (actually, this is technically the beginning of the covenant, but God made promises earlier). Here's how the conversation goes:
GOD: Don't be afraid, I am your shield, your very great reward
ABRAM: how can this be? i don't even have a child, the most basic blessing.
GOD: I will give you a son.
ABRAM: I believe.
GOD: I will give you this land
ABRAM: how can I know? I don't want to get my hopes up
GOD: I will meet you personally
Abram then gathers a sacrifice and prepares the offering for God. He sits and waits, and waits, and waits, and waits for it to rain (Silverstein, "Lazy Jane", Where the Sidewalk Ends. [give credit where it is due]). He chases away birds, which means the carcasses had been there for quite a while. Sitting in the stench, waiting on God's promises, Abram falls asleep. God speaks to him in his sleep, explaining that the land won't be immediate, in fact Israel will have to go through hell to get there. Abram wakes up (assumedly), and sees a firepot and torch floating through camp. Weird. God then makes the covenant for land and children official.
This is the promise Israel's hopes relied on throughout their history. Every time they were in exile, they clung to this hope. Every time they were feeling the consequence of their sin, they remembered that day. Every time they questioned God's answer, he reminded them of when Abram questioned too. When we doubt, question, and disbelieve, God wants us to remember his promises.
As far as a review goes, Eminem's new album is horrendous. Not only is the music disinteresting and simplistic, the lyrical content is devoid of all substance. There was a point at which Eminem rapped about his life, struggles, and hopes. Now he has been reduced to a pile of hormones driven to find happiness by pursuing meaningless sex. His honest hunger for truth, identity, and meaning has been temporarily fed at the worldly mcdonald's of sensuality rather than the satiating fountain that is the source of all Truth. Pray for him.