I shall soon have finished a non-stop run through Genesis. You may have heard it said that the Old Testament is the story of Israel's ongoing struggle against polytheism and idolatry, and it is mostly a struggle with self. Because polytheism was the way of men everywhere then, as it very much is today, and increasingly so. And it is the tendency of the chosen People to copy the culture they find themselves in and re-assume the idolatry that their ancestors had rejected. In the book of Genesis itself, we find that, although Abraham is extremely faithful to the one, true God, it is against a background of polytheism, and when Abraham encounters the three men in white in his vision in chapter 18 he recognises only one of these divine persons as the God he had encountered earlier (singular pronoun Thou), but nevertheless gives all three (plural pronoun You) an equal homage. This has led Christian authors to point to this event as an early appearance of the Holy Trinity:
"He looked up, and saw three men standing near him; and, at the sight, he ran from his tent door to meet them, bowing down to the earth. 'Lord,' he said, 'as Thou lovest me, do not pass Thy servant by; let me fetch a drop of water, so that You can wash your feet and rest in the shade. I will bring a mouthful of food, too, so that you can refresh yourselves before you go on further; you have not come this way for nothing.'" - Genesis, 18: 1-5
So, Abraham is taught devotion to the one God gradually, in the course of all those stories about him that we know so well: the gift of Isaac, the sacrifice of Isaac. Abraham wishes to preserve his son from the pollution of idolatry in the Holy Land and sends him off to Haran in Mesopotamia, to find a wife among his own clan, where the true God was worshipped (although, as one among others). Then, later on, Isaac is called to obedience of the God of his father Abraham, as if asked to choose this Deity over others he was probably surrounded with and attracted to. In fact, he is favoured as a result of Abraham's devotion, rather than his own:
"From there he went to Bersabee; and here, the same night, he had a vision of the Lord, who said to him, 'I am the God of thy father Abraham; fear nothing, I am with thee. I mean to bless thee, and give increase to thy posterity, in reward of Abraham’s true service.' So he built an altar, and invoked the Lord’s name, and pitched his tent there, and bade his servants dig a well." - Genesis, 26: 23-25
And when it came to Isaac's twin sons, Jacob and Esau, we find the old problem of infidelity to the God of Abraham, for Esau (to his parents' displeasure) married outside religion and so risked and endangered the blessing of God on the children of Abraham. Isaac's reaction was to send Jacob off to find a wife in Mesopotamia, once more. When Jacob had the vision of the staircase going to Heaven, he was in flight from his brother Esau (who meant to kill him), and he renamed the place he was at (Luza) as Beth-El (literally, the house of God), and promised God to be faithful only to Him if He were to protect him from Esau's rage:
"When he awoke from his dream, Jacob said to himself, 'Why, this is the Lord’s dwelling-place, and I slept here unaware of it!' And he shuddered; 'What a fearsome place is this!' said he. 'This can be nothing other than the house of God; this is the gate of Heaven.' So it was that, when he rose in the morning, Jacob took the stone which had been his pillow, and set it up there as a monument, and poured oil upon it; and he called the place Bethel, the House of God, that was called Luza till then. And there he took a vow; 'If God will be with me,' he said, 'and watch over me on this journey of mine, and give me bread to eat and clothes to cover my back, till at last I return safe to my father’s house, then the Lord shall be my God.'" - Genesis 28, 16-21
Through tribulation therefore, the ancient patriarchs were led towards devotion to the one God. Later, in chapter 31, we discover that Jacob's uncle Laban, whose daughters he had married, was himself a polytheist, for when Jacob travelled back to the Holy Land from Mesopotamia, his wife Rachel smuggled away some of her father's household gods:
"Upon this, Jacob waited no longer; he mounted his children and wives on the camels, and set out on his journey; taking with him all his possessions, his cattle and all the wealth he had gained in Mesopotamia; he would return to his father Isaac, and the land of Chanaan. Meanwhile, in the absence of her father Laban, who had gone to shear his sheep, Rachel stole his household gods from him. Jacob had given his father-in-law no warning of his flight, and it was not till he and all that belonged to him had gone away, and crossed the Euphrates, and were making for the hills of Galaad, that a message came to Laban, three days too late, Jacob has fled." - Genesis, 31: 17-22
And then we arrive at the point at which Jacob (now renamed Israel by God) decided to permanently consecrate not only himself but his entire family to the one God at Bethel, and I'll finish this post on the quote. The rest of the Old Testament is the story of Jacob's children falling away from and reconciling themselves to the one God, and that's one reason for the importance of the story of our Hebrew ancestors in the Faith: we have the same human inclinations to turn away from God, and we must repeatedly turn back towards Him. The picture below is the foundation story for Bethel (the end of Genesis 28).
"In the meanwhile, too, God had said to Jacob, 'Bestir thyself, go up to Bethel, and make thy dwelling there; there build an altar to the God who revealed himself to thee when thou wast in flight from thy brother Esau.' Whereupon Jacob summoned all his household; 'Cast away, he told them, whatever images of alien gods you have among you, purify yourselves, and put on fresh garments. We must leave this, and go up to Bethel; there we must build an altar to the God who listened to me in time of trouble, and escorted me on my journey.' So they gave him all the images of alien gods that were in their possession, the rings, too, which they wore on their ears, and he buried them under the mastic-tree, close to the town of Sichem. Thus they set out on their journey, and God inspired terror into the hearts of all who dwelt around them, so that they durst not pursue them as they went. Jacob, then, with all his clan, made their way to Luza, which is now called Bethel, and built an altar there. It was he who called the place Bethel, the house of God, because it was there God appeared to him when he was in flight from his brother." - Genesis, 35: 1-7
