Jacob, Isaac’s son, is one of the Bible’s greatest examples of how much a human being can change through the process of conversion. A pattern of sin and deception early in Jacob’s adulthood eventually disappeared as this great servant became something barely recognizable to those who had known him before his change. Turning from polygamy is part of this story.
The name Jacob means “supplanter.” Jacob did, in fact, supplant his brother Esau by unlawfully obtaining the birthright designated to the eldest brother through deception of their father—Isaac, then blind.
But Jacob later got what he gave when his father-in-law, Laban, terribly deceived him by supplanting his daughter Rachel—the one Jacob loved and was promised would be given to him in marriage—with his oldest daughter, Leah. Jacob became the victim of plain fraud, and the biblical laws of marriage permitted him to reject the marriage to Leah as soon as he discovered what his father-in-law had foisted on him. But he did NOT reject her as his wife. He accepted Leah, thus causing God to bind him to her as his wife—his only TRUE wife in the eyes of God from that moment forward.
Jacob did eventually also marry Rachel. And this occurred before he was converted—before he was seeking God’s wisdom, will and overall direction in his life. In this pre-conversion period, he was pursuing what he wanted rather than what God wanted. The result: Jacob not only lived a life of polygamy with two wives, but also had children by the two handmaids of these wives.
Genesis 32:24-30 describes the conversion of Jacob. Chapter 35 verses 2 through 4 describe his coming out of idolatry after God changed his name to ISRAEL. This new name meant “overcomer” or “prince of God—prevailer with God.” In time, God permitted Rachel to die (35:19), and Jacob remained faithful to his original and only real wife, Leah, for the rest of his life.
All people must turn from every form of sin, and polygamy was simply a sin like any other from which Jacob had to turn.