Talk briefly about the grim nature of the Parasha - Blessings and curses and the Tochacha
(11) Thereupon Moses charged the people, saying: (12) After you have crossed the Jordan, the following shall stand on Mount Gerizim when the blessing for the people is spoken: Simeon, Levi, Judah, Issachar, Joseph, and Benjamin. (13) And for the curse, the following shall stand on Mount Ebal: Reuben, Gad, Asher, Zebulun, Dan, and Naphtali. (14) The Levites shall then proclaim in a loud voice to all the people of Israel: (15) Cursed be anyone who makes a sculptured or molten image, abhorred by the LORD, a craftsman’s handiwork, and sets it up in secret.—And all the people shall respond, Amen. (16) Cursed be he who insults his father or mother.—And all the people shall say, Amen. (17) Cursed be he who moves his fellow countryman’s landmark.—And all the people shall say, Amen. (18) Cursed be he who misdirects a blind person on his way.—And all the people shall say, Amen. (19) Cursed be he who subverts the rights of the stranger, the fatherless, and the widow.—And all the people shall say, Amen. (20) Cursed be he who lies with his father’s wife, for he has removed his father’s garment.—And all the people shall say, Amen. (21) Cursed be he who lies with any beast.—And all the people shall say, Amen. (22) Cursed be he who lies with his sister, whether daughter of his father or of his mother.—And all the people shall say, Amen. (23) Cursed be he who lies with his mother-in-law.—And all the people shall say, Amen. (24) Cursed be he who strikes down his fellow countryman in secret.—And all the people shall say, Amen. (25) Cursed be he who accepts a bribe in the case of the murder of an innocent person.—And all the people shall say, Amen. (26) Cursed be he who will not uphold the terms of this Teaching and observe them.—And all the people shall say, Amen.
Amen - original meaning was "So be it" - whoever pronounces Amen to an oath, it as if he had pronounced the oath himself.
In later times, in shul, Amen became the standard response.
Some sources for saying Amen
למימרא דמברך עדיף ממאן דעני אמן והתניא ר' יוסי אומר גדול העונה אמן יותר מן המברך א"ל ר' נהוראי השמים כן הוא תדע שהרי גוליירין יורדין ומתגרין [במלחמה] וגבורים יורדין ומנצחין תנאי היא דתניא אחד המברך ואחד העונה אמן במשמע אלא שממהרין למברך יותר מן העונה אמן
The Gemara asks: Is that to say that one who recites a blessing is preferable to one who answers amen? Wasn’t it taught in a baraita that Rabbi Yosei says: The reward of the one who answers amen is greater than the reward of the one who recites the blessing?
Rabbi Nehorai said to him: By Heavens, an oath in the name of God, it is so. Know that this is true, as the military assistants [gulyarin]descend to the battlefield and initiate the war and the mighty descend and prevail. The amen that follows a blessing is compared to the mighty who join the war after the assistants, illustrating that answering amen is more significant than reciting the initial blessing.
(ב) הַשּׁוֹמֵעַ אֶחָד מִיִּשְׂרָאֵל מְבָרֵךְ אַחַת מִכָּל הַבְּרָכוֹת, אַף עַל פִּי שֶׁלֹּא שָׁמַע כֻּלָּהּ מִתְּחִלָּתָהּ וְעַד סוֹפָהּ, אַף עַל פִּי שֶׁאֵינוֹ חַיָּב בְּאוֹתָהּ בְּרָכָה, חַיָּב לַעֲנוֹת אַחֲרָיו אָמֵן; אֲבָל אִם הָיָה הַמְבָרֵךְ אֶפִּיקוֹרוֹס אוֹ כּוּתִי אוֹ תִּינוֹק, אוֹ הָיָה גָּדוֹל וְשִׁנָּה מִמַּטְבֵּעַ הַבְּרָכוֹת, אֵין עוֹנִין אַחֲרָיו אָמֵן. הַגָּה: וְעוֹנִין אָמֵן אַחַר עַכּוּ''ם, אִם שָׁמַע כָּל הַבְּרָכָה מִפִּיו (הר''י פֶּרֶק אֵלּוּ דְּבָרִים).
If a Jew hears someone say part of a bracha, even if he didn't hear the entire bracha from the beginning to the end and he is not bound by that bracha, he still has to say Amen...Rema - you even say Amen after a Gentile makes a blessing!
According to the Talmud (Shavuot 36a) . "amen" is related to the word "emunah," meaning truthfulness, credence or belief. When we hear another reciting a blessing we respond with "amen"; thus affirming that we believe that which has just been said - which more often than not, blesses Gd for everything he has provided us with.
In addition, amen (אמן) is an acronym for the Hebrew words א-ל מלך נאמן, (Kel Melech Ne'eman), meaning "G‑d, the trustworthy King."
Rabbis said "whoever says Amen with all of his strength, to him, the gates of Paradise will be opened"
The people saying Amen to the curses, was their declaring their belief in the the Torah as the ultimate guide to creating the values of a moral society. This was also a declaration of Gd's sovereignty over the world.
The people ratified this, by saying Kel Melech Neeman - Gd would punish those who brought immorality into society through their behaviour.
This was a continuation of Naaseh venishmah. We will do and we will listen.
Throughout our history, when we have suffered persecution, we questioned why this was happening to us. Yet, throughout the bad times, we have always used the power of Amen to boost the power of the brachot we make and hear. It is this belief that has kept us going to the present day.
Let us remember that the way forward, even through dark times is to always remember to say Amen!