You can’t force faith. It’s a fact. One can teach about beliefs and ideals. One can demonstrate living a life according to a strict moral code. But one cannot force someone else to believe in anything. This was something of which Avraham was well aware. Traditional texts record that Avraham and Sarah had many followers and that they were constantly teaching others about belief in the Creator, but what was most important to them was that each person find the opportunity, like Avraham, to truly find God on his or her own. The significance of this level of believe can be observed in the story of Rivka.
There is a seemingly odd discussion in the Gemara about whether Avraham had a daughter (Baba Batra 16b). One of the opinions is that Avraham had a daughter whom he called Bakohl, ” which means in or with everything. The Talmudic discussion is based on Bereishis 24:1, which says, “And Avraham was old, advanced in days, and Hashem blessed him with everything.” The play-on-words interpretation that Avraham was blessed with a daughter whom he named Bakohl comes from the supposition that to have been truly blessed with everything, Avraham would have sired both a son and a daughter.
Perhaps though, one could take this a step further and explain that the daughter with whom Avraham was blessed was his daughter-in-law Rivka. One could say, looking at the conversation between Avraham and Eliezer, that Avraham believed that Rivka, as a not-so-distant relative, had spiritual potential. The Torah tells us specifically that he knew of her:
Some time later, Avraham was told, Milcah too has borne children to your brother Nahor: Uz the first-born, and Buz his brother, and Kemuel the father of Aram; and Chesed, Hazo, Pildash, Jidlaph, and Bethuel” – Bethuel being the father of Rivka. These eight Milcah bore to Nahor, Avraham’s brother (Bereishis 22:20-23).
Avraham could have named Rivka as the one he wanted Eliezer to find, but instead of naming her to Eliezer, he sent Eliezer back to his homeland with only the main instructions to bring home a bride and to not agree, under any circumstances, for Yitzchak would go there. And Eliezer appears to understand, for he too refers only to “the woman,” leaving her specified yet undefined.
So why didn’t Avraham just tell Eliezer to go to Rivka? Because Avraham wanted to place no claim on her. For her to marry Yitzchak, she had to come completely of her own volition. To become Avraham’s daughter, she had to have her own Lech Lecha type of journey, and Avraham was setting the stage for this to happen by sending Eliezer to find a wife from his land, from his birthplace, and from his father’s house. There could be no hint of force or coercion in this process. It had to be completely from her heart and come from her soul; Just as today a convert must be completely sincere for the process to be correct.
But what if she said no? What if Rivka was not as strong as Avraham and Sarah had been? It was a possibility, and this, perhaps, was at the heart of Eliezer’s question of what if she won’t make the journey. Avraham recognizes this as a possibility, and this is why he is firm in his command that Yitzchak cannot go out of the Promised Land – so much so that he states it numerous times. If Yitzchak reverses Avraham’s journey, then all will be lost.
When Avraham sends Eliezer to Ohr Kasdim, he is “old and advanced in days.” He is ready to let a new generation take the lead, but for that he knows, better than anyone, that Yitzchak needs the right partner, and that partner must be one who can understand Avraham’s original journey. When he sends Eliezer to find Yitzchak a wife, he is completely confident that his family will be complete because he knows that Hasham has truly blessed him in everything.