Mark 12:28-34
28One of the teachers of the law came and heard them debating. Noticing that Jesus had given them a good answer, he asked him, “Of all the commandments, which is the most important?”
29“The most important one,” answered Jesus, “is this: ‘Hear, O Israel: The Lord our God, the Lord is one. 30Love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength.’ 31The second is this: ‘Love your neighbor as yourself.’ There is no commandment greater than these.”
32“Well said, teacher,” the man replied. “You are right in saying that God is one and there is no other but him. 33To love him with all your heart, with all your understanding and with all your strength, and to love your neighbor as yourself is more important than all burnt offerings and sacrifices.”
34When Jesus saw that he had answered wisely, he said to him, “You are not far from the kingdom of God.” And from then on no one dared ask him any more questions.
Arthur Green, quoted in Siddur Lev Shalem, p. 155
The core of our worship is not a prayer at all, but a cry to our fellow Jews and fellow humans. In it we declare that God is one- which is also to day that humanity is one, that life is one, that joys and sufferings are all one- for God is the force that binds them all together. There is nothing obvious about this truth, for life as we experience it seems infinitely fragmented. Human beings seem isolated from one another, divided by all the fears and hatreds that make up human history. Even within a single life, one moment feels cut off from the next, memories of joy and fullness offering us little consolation when we are depressed or lonely. To assert that all is one in God is our supreme act of faith. No wonder that the Sh’ma, the first “prayer” we learn in childhood, is also the last thing we are to say before we die
בֶּן עֲזַאי אוֹמֵר זֶה סֵפֶר תּוֹלְדֹת אָדָם, זֶה כְּלַל גָּדוֹל בַּתּוֹרָה, רַבִּי עֲקִיבָא אוֹמֵר (ויקרא יט, יח): וְאָהַבְתָּ לְרֵעֲךָ כָּמוֹךָ, זֶה כְּלַל גָּדוֹל בַּתּוֹרָה, שֶׁלֹא תֹאמַר הוֹאִיל וְנִתְבַּזֵּיתִי יִתְבַּזֶה חֲבֵרִי עִמִּי, הוֹאִיל וְנִתְקַלַּלְתִּי יִתְקַלֵּל חֲבֵרִי עִמִּי. אָמַר רַבִּי תַּנְחוּמָא אִם עָשִׂיתָ כֵּן דַּע לְמִי אַתָּה מְבַזֶּה בִּדְמוּת אֱלֹהִים עָשָׂה אוֹתוֹ.
Ben Azzai said: “These are the generations of Adam" is the great principle in the Torah.
Rabbi Akiva said: This is a great principle of the Torah: "You shall love your neighbor as yourself" (Lev. 19:18). Thus, one should not say, “Since I am scorned, I should scorn my fellow as well; since I have been cursed, I will curse my fellow as well.”
Rabbi Tanhuma says, “If you degrade any person, you should know who are you scorning — ‘in the likeness of God humanity was created.’”