via Reb Goldstein, as he heard from Rav Brizel…
In a certain town there was a barber who did not believe in G-d. When asked why, he responded, "Look at all the sick people, look at all the problems people have, how can there be a G-d if such things exist in the world!?"
Upon hearing this, the man he was speaking to turned around and began to shout out in the street, "I do not believe that there is a barber in this town, there is no barber in this town!"
The barber then stopped him and said with surprise, "But I am a barber, I am standing right in front of you. How can you say that you do not believe there is a barber here?"
To this the man responded, "I look around and see people with long hair, with messy hair, with dirty hair, since all these people have problems with their hair, it must mean that there is no barber in this town. To this the barber responded, "But what can I do, I can only help these people if they come to me."
The man said, "Hashem too can only help those who come to Him!"