The Ramban observes that Yitzchak Avinu’s love for Rivkah Imeinu was inspired by her righteousness and the suitability of her maasim tovim, good deeds, which are the only criteria upon which the Torah predicates the love between husband and wife. This is the only form of love that is enduring. Targum Onkeles interprets the pasuk: “When he/Yitzchak saw that her/Rivkah’s actions were similar to those of Sarah, his mother – v’nasiv es Rivkah, he married Rivkah.” Yitzchak’s decision to marry Rivkah, to have her become Klal Yisrael’s second Matriarch, was grounded on her spiritual similarity to his mother. He sought someone with whom he could establish the foundation for Klal Yisrael. The question is obvious: Eliezer’s mission was replete with miracles. From kefitzas ha’derech, the shortening of the journey; to meeting Rivkah immediately upon arrival; to the angel saving him from eating the poisoned food: nothing but miracles. When Eliezer returned to meet with Yitzchak, he related to him the entire litany of miracles that had occurred. Was there any greater, more compelling indication that Heaven was in support of this shidduch, match? What was Yitzchak waiting for?
The Brisker Rav, zl, explains that, for Yitzchak, miracles were insufficient in convincing him that Rivkah was the appropriate mate for him. It was only after he saw that her actions were similar to those of his mother that he agreed to marry her. The lesson is well-known: One does not marry because of miracles. One marries because of character and good middos, character traits.
Famous question, famous answer, but how does one argue with a Heavenly sign? If all the signs indicate this/she is the one, how does one ignore it? The answer is, the signs are a test. If one has criteria, he should adhere to them, because, at the end of the day, one marries the character, not the miracles.