(This is taken from the book in the right-hand column, "What Every Christian Should Know About the Jewish People." It would be beneficial to read the Overview first, here.)
The Jewish "High Holiday" season begins at sundown September 18th with the eve of the Jewish New Year, Rosh Hashanah (pronounced rush ha-sha-na and sometimes spelled Rosh Ha’Shanah). Synagogues will herald in the Jewish New Year with the blowing of the shofar, a trumpet-like musical instrument made from a ram's horn. Thus, Rosh Hashanah is also known as The Feast of Trumpets (“Yom Teruah”). The command from God to observe the Jewish New Year can be found in Leviticus 23:23:
The LORD said to Moses, "Say to the Israelites: 'On the first day of the seventh month you are to have a day of rest, a sacred assembly commemorated with trumpet blasts’.”
This year will be 5770 on the Jewish calendar, dating back to the beginning of Jewish recorded history.
Following Rosh Hashanah ten days later is the Jewish Day of Atonement – Yom Kippur (pronounced yome ki-poor'), from sundown on September 27th to sundown the next day. Every Jewish person who is “of age” (thirteen and over) is required to fast and refrain from any work for the entire twenty-four hours. Jewish people who observe this holiday may spend some of this day at a synagogue praying for God's forgiveness of sins, and approach people whose forgiveness they seek.
God's original command for Yom Kippur was this: "This is to be a lasting ordinance for you: On the tenth day of the seventh month you must deny yourselves and not do any work…because on this day atonement will be made for you to cleanse you. Then, before the Lord you will be clean from all your sins….” (Leviticus 16:29-30, excerpts, NIV).
From Rosh Hashanah to Yom Kippur are the “Ten Days of Awe”. Leading up to Yom Kippur, Orthodox Jews recite the “slichot”, prayers of repentance.
Can Christians commemorate Rosh Hashanah and Yom Kippur?
Christians and “Jewish believers in Jesus” should agree that all people who believe in God need confession and repentance. The Jewish observance of Yom Kippur is a serious thing not to be taken lightly.
Although Christians believe that Jesus Christ was the ultimate sacrifice for all sins (Romans 6:10) , we can still commemorate the Jewish Day of Atonement as a reminder to be truly repentant. Our attitude in demonstrating to our friends of Jewish and other faiths that we know the difference between right and wrong, is a good witness, a picture worth 1000 words.
Now, say to your Jewish friends "Shanah Tovah" (have a great Jewish New Year)!