According to the brilliant Kabbalistic theology of Rav Yehuda Lev Ashlag, z'l, the purpose of Creation is for human beings to become “like” Hashem through affinity of form. This is the ultimate good, the pleasure and delight, that Hashem wished to bestow on us, and is the reason for Creation. The “affinity of form” Rav Ashlag is referring to consists of developing the ratzon l' hashpia, or “desire to give benefit”. Hashem, needing nothing, has only a ratzon l' hashpia, and he has created us with a ratzon l' kabel, a desire to receive. By developing our own ratzon l' hashpia we attain greater affinity of form with HaKadosh Baruch Hu until finally we are able to receive in order to give- a state in which we are both givers of benefit to others, and thus like Hashem, and receivers of the “delight and goodness” which Hashem intended to give us. This is outlined in Rav Ashlag's Introduction to the Perush HaSulam, his commentary on the Zohar, and other works.
Rav Ashlag states further, in Matan Torah, that the Avot (and logically the Imahot) did not recieve the practical Torah (the actual mitzvot) but rather warranted the ruchniyut of the Torah, the spirituality of the Torah, because of their loftiness of soul. This loftiness of soul consisted, of course, in the ratzon l' hashpia, the desire to give benefit. The R”H is known also as “Ve'ahavta L' Reacha Kamocha”, loving your neighbour as yourself, which Rav Ashlag affirms is the klal gadol b' Torah, which he interprets to mean the one mitzvah which the entire Torah comes to bring into being and complete. The Avot and Imahot, while not possessing the practical mizvot of the Torah, did possess this one mitzvah as an expression of “the loftiness of their neshamot (souls)”. It was this loftiness which led Hashem to choose them and bless them to be the parents of Israel, and it was on its account that Israel warranted to receive the Torah, whose whole purpose is to purify Israel so they can develop the R”H, and thus attain d'vekut with Hashem (affinity of form, as the Gemarra also defines d' vekut).
This is reflected strongly in the chesed (kindness) of Avraham, and is also reflected this week in the detailed narrative of Eleazar and Rivka. Avraham, on his death bed, tells Eleazar, his servant, to leave Canaan and travel to Avraham's relatives, to see if he can find a wife for Yitzhak there. In the view of the Torah, the customs of the Canaanites are not those of Avraham's family, and he wants a wife from his people and their way of life. Eleazar chooses, as his sign, that the woman should spontaneously offer him and his camels water to drink. In other words, she will practice the Hesed of Avraham. Despite being “merely” the servant of Avraham, Eleazar seems to understand his ways well. He knows that Avraham is not merely interested in a relative, but rather a relative who embodies the code of his family- a code of chesed and righteousness. Eleazar finds that person in Rivka.