If you choose to celebrate them then it should be done as a beleiver with the focus on the future and return of the Lord. If we are without the knowledge of the Temple and the Feasts we can not fully understand the New Testament. So lets get started and learn about the feasts. According to Jewish tradition, people are judged on Rosh Ha-Shanah for their deeds of the past year. On Yom Kippur, Jews fast, express their regret for past sins, and declare their hope to perform good deeds during the coming year.
Many Jewish festivals commemorate major events in Jewish history.
For example, Passover celebrates the Exodus of the Jews from Egypt. Jews celebrate these festivals both in synagogues and at home. The High Holidays, called Rosh Ha-Shanah and Yom Kippur, are the most sacred days of the Jewish year. Like all Jewish holidays, they occur on different dates each year because they are based on the Hebrew calendar. The High Holidays come during Tishri, the first month of the Hebrew calendar, which usually falls in September or October.