The “Shema” can refer to Deut. 6:4, or Deut. 6:4-9 (including “the V’Ahavta”), or Deut. 6:4-9 and Deut. 11:13-21 (the “V’haya Im Shamo’a”) and Num. 15:37-41 (the “Vayomer”). It is said in the morning and evening service (Mishnah Brachot 1:3), as well as when one lies down to sleep and when one gets up from sleep (per what it says in Deut. 6:7), as well as when you are about to die (just Deut. 6:4). The Shema was originally put together not as a prayer but as a "recitation" ("kriya") of key Torah passages that expressed basic Jewish dogma, such as there only being one god and that love of G-d was the best motivator for serving G-d. This happened during the period of the Second Temple and was in place by 1 BCE, because Hillel and Shammai discuss it (Mishnah Brachot 1:3; Mishnah Tamid 5:1)
It's 1933 in Germany. A Jew has been dismissed from his job because he is Jewish. He worries how he's going to help feed his family when he sees an advertisement for a circus coming to town. He goes and convinces them to let him dress up in a lion suit and fight wild animals. He figures that if he gets paid in advance, at least he'll send home one more paycheck before he dies.
His first day comes and he bounds into the ring in his lion suit. A fierce tiger comes roaring at him and he knows this is his end. He starts to say Shema Yisrael, and he hears the tiger finish it for him. "What? You think you're the only Jew trying to make a living?
בְּשָׁעָה שֶׁמַּעֲבִיר יָדָיו עַל פָּנָיו, מְקַבֵּל עָלָיו עוֹל מַלְכוּת שָׁמַיִם.
When Rabbi Yehuda HaNasi passed his hands over his face in the study hall in the middle of his lesson, he accepted the yoke of the kingdom of Heaven upon himself, as his Shema was comprised of a single verse.
Note that when the Romans forbade the Jews from saying the Shema, the Jews hid it in other parts of the service. That is why the Shema can be found in Birchot haShachar, the Torah Service, the Musaf Kedushah, and Tachanun (broken up in "Shomer Yisrael"). This is also why we don't cover our eyes at those points. (Kippa tip to Cantor Neil Schwartz for this)
From this origin, other ideas have been layered on to derive meaning from this custom. For instance, seeing emphasizes that which is external, while hearing emphasizes that which is internal, and we are asked to internalize our experience of G-d. Alternatively, our god is invisible, so we reduce what we can see at this point.
It is customary to use our dominant hand to cover our eyes. Some simply shield their eyes, while others completely cover them. This choice of hand may be connected to the fact that the non-dominant hand was used for wiping in the bathroom in the ancient world.
(ד) שְׁמַ֖ע יִשְׂרָאֵ֑ל יְהֹוָ֥ה אֱלֹהֵ֖ינוּ יְהֹוָ֥ה ׀ אֶחָֽד׃
(4) Hear, O Israel! יהוה is our God, יהוה is one.
שְׁמַ֖ע
Hear / Listen / Pay attention
It can be hard to give somebody our full attention when there are so many ways to multi-task (like with devices). Who's somebody you can make sure to give your full attention to?
יִשְׂרָאֵ֑ל
O Israel
What's a key thought from your life that you want to make sure is passed on?
יְהֹוָ֥ה אֱלֹהֵ֖ינוּ
הוה is our God
How did G-d become your god?
יְהֹוָ֥ה ׀ אֶחָֽד׃
יהוה is one
Note that some have the custom to prolong the word "echad", either to give them time to ponder the oneness of G-d (per the Babylonian Talmud, Brachot 13b) or to make sure that they are emphasizing the "daled" so it's clear they aren't saying "acher" ("other").
Can you describe the G-d you believe in? Can you describe the G-d you don't believe in?
(ג) בלחש - בָּרוּךְ שֵׁם כְּבוד מַלְכוּתו לְעולָם וָעֶד:
Praised be the name of the One whose glorious sovereignty is forever and ever.
In Pirkei Avot it is said that there are 3 crowns -- the crowns of Torah, priesthood, and royalty -- but the crown of a good name surpasses them all (4:13 or 4:17, depending on your version). Who would you say has "the crown of a good name", and why?
(5) You shall love the Lord your God with all your heart and with all your soul and with all your might.
The Hebrew word for "heart" is "lev". The word here for "your heart" is "l'vavcha", with a second letter "vet". This has been said to mean that we should use both the good inclination (yetzer hatov) and bad inclination (yetzer hara) in our hearts to love G-d.
"With all of your soul" could mean "all parts of your soul", and it can also mean "all the days of your soul on this earth". When Rabbi Akiba was being martyred by the Romans, he seemed almost happy. When his students asked him about this, he said that for many years he had wondered when he would get to fulfill this part of the V'ahavta, and now he finally could. He died as he finished saying the Shema. (Brachot 61b). Even if we don't get martyred, we can still love and serve G-d all the days of our life.
The word "me'odecha" can mean "your might", but it can also mean "your very-ness" (kippa tip to Adam Schwartz). What is "your very-ness" and how can you use it to serve G-d?
(6) These words with which I charge you today shall be on your heart.
Depending on how you punctuate this verse, it can read "These words which I charge you today, shall be on your heart" or "These words which I charge you, today shall be on your heart." If you go with the second interpretation, it can also be viewed in two different ways. The first is "These words shall be on your heart today, but not tomorrow", or "These words shall be on your heart today and don't wait until tomorrow".
What's something that your "yetzer hatov", "good inclination" tells you you should take to heart today and not wait for tomorrow?
(7) Teach them to your children. Speak of them when you stay at home and when you are away, when you lie down and when you get up.
How can Judaism be relevant when you are "away"?
Note that because here tefillin are described as an "ote" (sign) of our relationship with G-d, and in V'shamru, in Exodus, Shabbat is described as an "ote" of our relationship with G-d, we don't wear tefillin on Shabbat lest Shabbat seem like an insufficient sign.
How can you use your hand and head to serve G-d?
Also, this verse does not refer to the gate of a house, but rather city gates. Archeology has found Near Eastern cities with the laws inscribed on the entrance to the city.
While traditionally one touches and kisses a mezuzah upon passing it, the Sephardic Chief Rabbi of Israel ruled in 2020 that this should be suspended during the Coronavirus Pandemic because preserving life is more important.
How would your life change if you received a notification every time you walked though a doorway in your home, reminding you to act as if you loved G-d?
Consider how these different versions make you feel.

