Below are two versions, a short one and an expanded version, of a 9/11 Lesson that I compiled a number of years ago. It connects the message of Rabbi Eliezer in Mishnah Avot and Gemara Shabbat to "Do Teshuva One Day Before You Die" with a famous poem that circulated the Internet for years after 9/11. When I teach this, I emphasize that Judaism is a religion that celebrates life and the message really is that one should live every day with no regrets. As the poem ends, "Take time to say "I'm sorry,""Please forgive me," "Thank you," or "It's okay."And if tomorrow never comes,you'll have no regrets about today."
Here are the lessons:
911 Lesson- Teshuva
Longer Source Sheet:
911- Do Teshuva One Day Before You Die