Rav Avigdor Nebenzahl – writes:
We begin our Shmone Esrei with Baruch Ata Hashem Elokenu v’Elokei avotenu Elokei Avraham, Elokei Yitzchak, ve’Elokei Yaakov: Blessed are You, Hashem, our G-d and the G-d of our forefathers, G-d of Avraham, G-d of Yitzchak, and G-d of Yaakov. Why do we need to mention that Hashem is G-d of all three forefathers? Would it not have sufficed to say Elokei Avraham or at the very most Elokei Avraham, Yitzchak, v’Yaakov? Why do we make a separate mention of Hashem as the G-d of Avraham, the G-d of Yitzchak, and the G-d of Yaakov? The phrase Elokei Avraham, Elokei Yitzchak, v’Elokei Yaakov actually appears in the Torah (see Shmot 3:6), if so the question remains; why does the Torah describe Hashem as the G-d of each of the forefathers separately?
Each of the forefathers had his own unique understanding of Hashem and how to spread word of His existence. Avraham Avinu, as we mentioned, epitomized the Attribute of Chesed. We spoke last week about Noach’s chesed but Noach only had animals to do chesed with. Avraham introduced the idea of chesed with human beings. Yitzchak Avinu was certainly a man of chesed but the Attribute he focused on was the one of din, Judgment. Yaakov personified the trait of rachamim, mercy which lies between chesed and din. Each had his own unique way of knowing and teaching about Hashem, with one emphasizing chesed, one emphasizing din, and one emphasizing rachamim.
Rabbi Dessler in Strive for Truth – Vol 5 (page 53) takes this a step further:
Generally a person’s character is based mainly on one of the three dominant forces discussed above. We usually find that all a person’s thoughts and deeds are influenced and guided by his dominating quality.
When a person decides to devote his life to the service of Hashem, his first act should be to discover and recognize his dominating quality. He should then try to develop it, perfect it and remain true to it to the best of his ability. But he should not be satisfied with this. There are other qualities hidden within him, and to reach his full potential he must try to develop these too.