Kaddish, literally “the sanctification,” is a prayer that dates back to the Mishnaic period, at least 1,900 years ago. It expresses our conviction that no matter what happens, and despite all the tragedies and sorrows of this world, ultimately there will come a time when God’s existence will be apparent, and His Name will be on everyone’s lips.
The chazzan (prayer leader) recites this declaration at the end of every major segment of the prayers along with a request that God should accept our service and our prayers.
Mourners also recite Kaddish several times during the service. By saying Kaddish they reaffirm their belief that despite the loss of an individual, God’s purpose will be fulfilled through the Jewish people as a whole.
For this reason, Kaddish is recited only in the presence of a community (a minyan), never privately. Although individuals die, the community will never perish. Throughout the generations, the Jew has been sustained by this conviction; for even when an individual experiences a difficult loss, he is reminded that he is part of an eternal unit, that every single part of that unit was created for a purpose, and that ultimately the purpose will be realized.