Baruch atah Hashem, Elokeinu Veilohei avoteinu, Elokei Avraham, Elokei Yitzchak, Veilokei Yaakov, haE-l hagadol hagibor vehanora, E-l Elyon, gomel chasadim tovim vekoneh hakol, vezocher chasdei avot, u-mevi goel livnei veneihem, lema-an shemo be-ahavah
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; the great, mighty, and awesome G-d, the supreme G-d, Who bestows beneficial kindnesses and creates everything, Who recalls the kindnesses of the Patriarchs and brings a Redeemer to their children's children, for His Name's sake, with love.
Melech ozer u-moshia u-magen
O King, Helper, Savior, and Shield.
Baruch atah Hashem, magen Avraham
Blessed are You, Hashem, Shield of Avraham.
The Avot blessing is the introductory blessing of the Shemoneh Esrei. In this first blessing we introduce ourselves to the Almighty and present to Him our credentials.
By calling Him "our G-d" we identify ourselves as His faithful followers. We then mention our yichus ("family lineage"), our relationship with Avraham, Yitzchak, and Yaakov, with whom He had established a special covenant and to whom He made certain promises that involve their descendants.
And so we, the descendants, now humbly claim His protection, not because of our own virtues, but because of the merit of our forefathers (Yoma 87a).
Talmud - Mas. Yoma 87a
Happy are the righteous! Not only do they acquire merit, but they bestow merit upon their children and children's children to the end of all generations, for Aharon had several sons who deserved to be burnt like Nadav and Avihu, as it is said: ‘That were left’;10 but the merit of their father helped them.
10) VaYikra 10:12, the suggestion being ‘they were left to survive’, having also deserved the punishment suffered by their two brethren.
We resort to the same defense that Moshe had recourse to when the Yisraelim sinned by worshiping the Golden Calf. The Torah tells us that G-d expressed a wish then to destroy the entire nation, but Moshe pleaded with Him on the Yisraelim behalf. At first, G-d was adamant in His refusal. Only when Moshe said: "Remember Your servants Avraham, Yitzchak, and Yisrael" (Shemot 32:13) did G-d finally accept his prayer (Shabbat 30a; Berachot 32a).
Talmud Bavli - Shabbat 30a
...when Yisrael sinned in the wilderness, Moshe stood before the Holy One, blessed be He, and uttered many prayers and supplications before Him, but he was not answered. Yet when he exclaimed, ‘Remember Avraham, Yitzchak, and Yisrael, your servants!’ he was immediately answered.
Talmud Bavli - Berachot 32a
Remember Avraham, Yitzchak and Yisrael Your servants, to whom You did swear by Yourself.23 What is the force of ‘by Yourself’? R. Eleazar said: Moshe said before the Holy One, blessed be He: Sovereign of the Universe, had You sworn to them by the heaven and the earth, I would have said, Just as the heaven and earth can pass away, so can Your oath pass away. Now, however, You have sworn to them by Your great name: just as Your great name endures for ever and ever, so Your oath is established for ever and ever.
23) Ibid. 13
We depend on this special relationship when expressing our conviction that G-d can be relied upon to bring redemption to the Jewish people.