In the 1940s, Leibel Posner, a student in the central Chabad-Lubavitch yeshivah, met a student, a brilliant individual, who claimed that people bore him. Leibel conversed with the boy in one of their first meetings for over five hours. Leibel did most of the talking. Much of the conversation revolved around the young man's assertion that he found it difficult to accept the existence of a G‑d who cannot be seen by the human eye.
Leibel mentioned the conversation to Rabbi Menachem Mendel Schneerson (later to become the seventh Chabad Rebbe upon the passing of his father-in-law in 1950). The Rebbe said to Leibel that it was recently discovered by scientists that every object is made up of atoms that cannot be seen to the human eye. So even though you can't see the atoms, the human mind has become "intelligent" to apprehend something that cannot be seen. And any person who does not accept this theory is considered one that is not speaking with logic!
He then explained to him how to explain the belief in a G‑d that we cannot grasp in our mind:
"There is a subway here in New York and an elephant in Africa. You have seen both. So could you imagine the elephant in the subway? You can. However if you lived in Poland and you do not know what an elephant or a subway is, could you imagine an elephant in a subway? If you do not know what it is you cannot imagine it. But you cannot imagine it, does it mean that it does not exist?"
Upon Leibel's request the student came to see the Rebbe. They spoke for three hours. The Rebbe convinced him to put on tefillin every day.
A short while later the Rebbe asked Leibel if the young man is putting on tefillin. But when Leibel spoke with him, he said that he hadn't actually promised to put on tefillin, only that he would consider doing so.
Years later, the Rebbe sent Leibel to California to help the Chabad emissary there, Rabbi Shmuel Dovid Raichik. On that occasion, the Rebbe also asked him if he knows what is happening with that young man. Leibel said that he lost contact with him, but he would make an effort to track him down.
Leibel found out that he was in Los Angeles, and decided he would make contact with him there. After finally reaching him on the phone, they made a time to meet, but the man never showed up to the meeting.
When Leibel returned to New York for a visit, the Rebbe asked him, did you meet him? Leibel answered that unfortunately he did not.
On his return to Los Angeles he tried once again to meet with him, again without success. Leibel was still trying to reach him when he found out that the young man committed suicide.
