YOM KIPPUR
We acknowledge the departure of the "Shekhina," the Divine Presence, with a "Tekiah Gedolah!" a Great "Tekiah," a long straight blast of the Shofar. At this time, there is no room for sighing or wailing. We have hopefully been forgiven, and our sins have been atoned for. We look forward to our Redemption; May it come in the blink of an eye!
The Shema
During the Shema on Yom Kippur, the second line, Baruch Shem Kavod Malchuto LeOlam V’aed, "Blessed is the Name of His Glorious Kingdom for all eternity" is read aloud. Moshe originally heard this line from the angels when he was on Mount Sinai receiving the Torah from G-d. Though normally said quietly, on Yom Kippur it is said out loud. Normally, we dare not utter angelic phrases loudly, but on Yom Kippur, it is as if we are spiritually raised to the level of angels and we say the verse out loud.
As the Rav Issac Luria, 16th Century Kabbalist, wrote that confession is written in the plural, "We have sinned‘ because all Israel is considered like one body and every person is a limb of that body. So we confess to all the sins of all the parts of our body.  Daniels prayer in chapter 9 was on Yom Kippur.
On Yom Kippur, yet a fifth service (the only day of the year with 5) is added. The extra service unique to Yom Kippur is called Neilah.
Neilah is said after Mincha as the sun is going down and  literally means closing (or locking) and refers to either the closing of the gates of the Holy Temple at the end of the day or it refers to the closing of the gates of prayer as Yom Kippur is ending .
The Neilah service contains stirring pleas that our prayers be accepted by G-d before Yom Kippur ends. The heavenly judgment inscribed on Rosh Hashanah is now sealed during Neilah. The chazan chants the service in a special melody designed to stir the emotions and bring the congregation to greater devotion.
Following the Maftir, the Haftorah is read. The Haftorah is from Yeshayahu (Isaiah) Chapter 57: verse 14 until Chapter 58, verse 14. Isaiah urges the Jewish People to return to Hashem through good deeds, kindness and sincere Teshuvah.
The Torah reading is from Vayikrah (Leviticus) Chapter 18, verse 1-30. The portion deals with forbidden sexual relationships. Though the exact reason for reading this section now is not entirely clear, here are some possible reasons. 1) They are read now because everyone is in shul. 2) It is as if to say, "Though right now you are on a lofty spiritual level on Yom Kippur, don’t think you cannot drop down in a second to the worst abominations. 3) The cornerstone of morality is self-control over animal sensuality (Hirsch)
Following the three aliyahs, the Haftorah is read. The Haftorah is the book of Yona (Jonah). Though everyone knows that a large fish swallowed Yona, the message of Yona is actually a timeless lesson in the power of Teshuva and G-d’s desire to help man rather than punish him.
Look at Luke 21:36 Jesus is referring to Yom Kippur. This is what is sought in the 10 days of Awe, to cleanse oneself, to be in white, to stand in His presence.