Summary: As servants of the Lord we need to be on constant watchful guard against the subtle ways the enemy uses to divert us from God's purpose and to nullify any effectiveness we may have had in influencing others for God.
And Abram went up out of Egypt, he, and his wife, and all that he had, and Lot with him, into the south. And Abram was very rich in cattle, in silver, and in gold. And he went on his journeys from the south even to Bethel, unto the place where his tent had been at the beginning, between Bethel and Hai; Unto the place of the altar, which he had made there at the first: and there Abram called on the name of the Lord.
And Lot also, which went with Abram, had flocks, and herds, and tents. And the land was not able to bear them, that they might dwell together: for their substance was great, so that they could not dwell together. And there was a strife between the herdmen of Abram's cattle and the herdmen of Lot's cattle: and the Canaanite and the Perizzite dwelled then in the land. And Abram said unto Lot, Let there be no strife, I pray thee, between me and thee, and between my herdmen and thy herdmen; for we be brethren. Is not the whole land before thee? separate thyself, I pray thee, from me: if thou wilt take the left hand, then I will go to the right; or if thou depart to the right hand, then I will go to the left. And Lot lifted up his eyes, and beheld all the plain of Jordan, that it was well watered every where, before the Lord destroyed Sodom and Gomorrah, even as the garden of the Lord, like the land of Egypt, as thou comest unto Zoar. Then Lot chose him all the plain of Jordan; and Lot journeyed east: and they separated themselves the one from the other. Abram dwelled in the land of Canaan, and Lot dwelled in the cities of the plain, and pitched his tent toward Sodom. But the men of Sodom were wicked and sinners before the Lord exceedingly. (KJV) Gen 13:1-13
In the previous chapter Abraham had gone to Egypt, because there was a famine in the land that had been promised to him by Yahweh! It was a very natural decision, for a man concerned about his family's welfare. But therein lies the error! Making natural decisions in major situations without consulting or seeking the will of God! Major situations come up constantly. Marriage, family, homes, transactions, careers, education, are just a few! The Bible says: Trust in the LORD with all thine heart; and lean not unto thine own understanding. 6 In all thy ways acknowledge him, and he shall direct thy paths. Proverbs 3:5-6 KJV
Abraham because of his natural choice however, had to engage in very compromising arrangements, in order to secure and protect his own skin. In the process he endangered his heritage, the chastity and safety of his wife, Sarah, and the general future of the world!
Thanks to God's grace, Abraham was able to get back on track. He was allowed to leave Egypt in safety, and with great wealth. However, he also took some of Egypt back with him, a sad consequence of his misadventure! An Egyptian maid named Hagar came back with his wife. We know how that ended!
Also the sophistry and culture of Egypt most likely brought back powerful memories of Ur to his immediate relatives, Lot and his family. The impact of Egypt reminded Lot's family of what they had left and dissatisfaction stepped in. It spilled over and influenced some decisions that had tragic consequences for Lot and his family!