Yom Kippur is considered the holiest day of the Jewish year and is observed by most Jews, regardless of their level of observance or religious background. The name literally means "day of atonement" and is a 25 hour period from sunset to nightfall when we have the opportunity to be cleansed of all sins before G-d. The day is based on the Torah verse that says in part "...on the 10th day of the seventh month it is the day of kippurim unto you...". Kippurim is also defined as "cleansing". According to Jewish tradition, G-d inscribe's each person's fate into the Book of Life on Rosh Hashanah for the following year, and then "seals" the verdict on Yom Kippur.
The 10th day of Tishrei, also commemorates the day Moses came down from Mount Sinai, for the second time, after seeking forgiveness and divine favor from G-d following the Israelites' sin of the Golden Calf. For this reason it is considered by many a day of reparation and Atonement.
Spiritually, there is a cosmic opening on this date that allows us to access the realm of Binah, an energy source filled with unconditional love, joy and blessing. The sephirot of Binah is our highest possible connection from the physical world allowing for complete union with the Light. By using ancient tools to connect to this source of Light in the upper worlds, we literally become one with G-d, cleansing ourselves from any past sins or selfish actions. When Moses came down from Mt. Sinai on the 10th of Tishrei, he created a space for mercy and love between humanity and the Creator. For this reason it is also considered a day of "At Onement".
On the 1st of Elul, 40-days before Yom Kippur, we begin to blow the Shofar every morning. This connects us to the 40-days Moses was on Mt. Sinai and starts to prepare us for the ultimate connection on Yom Kippur.
Kaparot - This atonement ritual is practiced the night before (erev) Yom Kippur by waving a chicken or money over your head three-times and saying certain prayers. The chicken or money is a vehicle through which we can atone and both the chicken or the money are given away to charity with an elevated state due to our exchange.
Honey Cake - Honey-cake is typically eaten on Rosh Hashanah and erev Yom Kippur to connect us to a sweet New Year
Mikveh - It is customary for all men to enter a mikvah (ritual pool) on the day before Yom Kippur to become cleansed and purified before the holiday and connect to the Light of Binah. The same way a convert becomes a "new person" in a mikvah, we too become new people by repenting, removing negativity and forgiving others during this time.
Extra Tzedakah - It is customary to give Tzedakah (charity) during the holidays, but even more so on Yom Kippur. Tzedkah is a source of blessing and protects us against harsh decrees. By giving away money (ideally anonymously) before Yom Kippur, we go against our nature and our connection to the physical. We are then better able to access the spiritual realms and clean our vessel for the upcoming year.
Restriction - In order to make spiritual connections and connect to the Light through our daily actions, we restrict certain behaviors. On Yom Kippur, we shutdown our relationship to physicality to connect to the Light for the coming year. In addition to the restriction against work like Shabbat, there are 5 specific prohibitions that help us to make our connection:
no food or drink;
no physical relations;
no perfumes; and
no wearing of leather shoes
By eliminating our connection to the physical dimension and using the Yom Kippur prayers we can access the Light of Binah and enjoy the feeling of At Onement without distraction.
Five Meals - Although we do not physically eat during Yom Kippur, our prayer connections are our spiritual meals for the day. On normal days, we have three prayer connections or meals - (1) Shacharit (morning), (2) Mincha (aftenoon) and (3) Arvit or Maariv (evening); on holidays we add an additional 4th prayer - Musaf. It is only on Yom Kuppur, that we add a 5th prayer called Neilah. The 5 meals or prayers connect us to the 5 levels of our soul (Nefesh, Ruach, Neshama, Chaya and Yechida) and help us move from the physical to the spiritual realm. The word "Soul" also appears five times in the Yom Kippur section of the Torah.
G-d's Holiest Name - Kabbalists use the tetragrammaton, the 4-letter name of G-d (YKV and K) to connect to His essence. The 10th day of Tishrei connects us to the letter Yud, the number 10, while the 5 prayers recited on Yom Kippur connect us to the letter Hei, the number 5. Yud and Hei are the first two letters of this holy name and are a distinct permutation of the Tetragrammaton which can be used to connect on Yom Kippur.
Baruch Shem Kevod 3 Times Out Loud - While we typically recite "Baruch Shem Kevod Malchoto L'olam Voed" a line from the Shema blessing, in an undertone, we say it loudly 3 times at the end of the Yom Kippur service. Kabbalists share that Moses overheard the angels praising G-d with theses words (“Blessed be the name of the glory of His kingdom forever and ever") when he visited G-d to receive the Torah. He brought it back to people to use in their daily prayers, but it is only on Yom Kippur when we have prepared ourselves and bathed in the Light of Binah, that we are like the angels and can say it out loud.
Final Shofar Blast - On Rosh Hashanah, we blow the shofar 100 times. We conclude the Yom Kippur Service with one long and final blast which marks G-d's ascension back to the higher realms after communing with us along our path to Binah throughout the holiday. The blast also signifies G-d's acceptance of our prayers, forgiveness of our sins and inscription into the Book of Life. The blast marks the end of the fast and our day of holy restriction.
Use these tools and deeper understanding about the holiday to have a powerful Yom Kippur connection!