Rosh Hashana Prayers and Customs
May everything that has been made, know that You made it.
In the future, when Moshiach comes, every creation will understand and recognize that within everything in this world there is a G-dly power which makes it exist and gives it its life-force. This is the meaning of this prayer which we say on Rosh Hashana. We beseech G-d to reveal His Kingship in this world - "May everything that has been made, know that You made it" - because in truth nothing exists without this G-dliness. (Rabbi Shneur Zalman of Liadi)
This is the day which is the beginning of Your work.
The world was created on the 25th of Elul. Rosh Hashana, the first of Tishrei, is therefore the sixth day of Creation. How, then, can we say about Rosh Hashana, "This is the day which is the beginning of Your work"? The fact of the matter is that the entire purpose of Creation was to make a "dwelling place below" for G-d and this is accomplished through man. Because of this, before man was created, it is impossible to say that the world existed in the true sense, for its purpose was still missing. Therefore, the sixth day of Creation, on which man was created, is "the beginning of Your work." (Likutei Torah)
As a young boy, the Previous Lubavitcher Rebbe, Rabbi Yosef Yitzchak, asked his father, the Rebbe Rashab, what he was supposed to be doing on the day before Rosh Hashana. "We recite Psalms the whole day long and feel remorse for our misdeeds of the past year, so that by the time evening falls and the new year begins, we are free of all our bad habits," his father replied.