In the Passover Haggadah, we read about the questions of the four children: one wise, one wicked, one simple and one who doesn't even know how to ask questions. The Rebbe has spoken numerous times about the four children and their relationship to all Jews today:
What unites the four children is the fact that they have all come to the Seder table. Even the wicked child comes, albeit asking his question, "What is the meaning of this service to you?" At least he has some connection to Judaism, however small or negative it may be.
Nowadays, in our generation, we have the phenomenon of a fifth child. This is the Jew who is so far removed from Judaism that he does not even know that there is such a thing as a Seder, or if he does know, chooses not to attend one. He might not even know that it is Passover! This Jew is not included among the four children because he is not even present.
Our obligation, the obligation of our generation, is to find these "fifth children" and draw them closer, with love and affection, to Torah, Judaism, and Mitzvot.
Years ago, and probably even today, some people used to symbolically leave an empty seat at the Seder for Jews who could not attend a Seder because of oppressive governments.
Although this is a beautiful gesture, it would be so much more appropriate to set aside a seat—and fill it—for a fifth child, someone who would otherwise not be attending a Seder.
A kosher and happy Passover to all of our readers. May we celebrate this year in Jerusalem!