Despite the fact that he was “afflicted […] with great plagues” (Gen. 12:17) because Abram lied to him, Pharaoh let him leave with all his possessions (possessions that, I remind you, Abram gained by forcing his wife into prostitution). So when Abram left Egypt and headed back toward Canaan, he “was very rich in cattle, in silver, and in gold” (Gen. 13:2). Lot, too, apparently did well for himself. He’s coming along with his “flocks and herds and tents” (Gen. 13:5).
But being so wealthy has its share of problems. When Abram and Lot get to Bethel (where Abram had built an altar before going on into Egypt), they find that the land cannot support so many “flocks and herds and tents” (Gen. 13:5). You know you have a lot of tents when you can’t fit all of them in a large plot of land. “Their possessions were so great that they could not dwell together” (Gen. 13:6).
This starts to cause strife between their herdsmen, so Abram proposes that they go their separate ways. Lot “chose for himself all the Jordan valley” and “moved his tent as far as Sodom” (Gen. 13:11, 12). Unfortunately for him, “the men of Sodom were wicked, great sinners against the Lord” (Gen. 13:13), but more about that later.
After Lot leaves, Abram pitches his tent in the land of Canaan, which God promises he will give to him and his descendants “for ever” (Gen. 13:16). This is rather confusing since, as we know, the land that was then known as Canaan has only belonged to Hebrews for a few spurts a couple times in history. In addition, says God, Abram will have as many descendants as there is dust on the earth (Gen. 13:16).
Abram dutifully builds an altar to the God who just lied to him.