In accordance with Jewish tradition, out of respect, I do not write G-d's name, even an English substitute, in a place where it may be discarded or erased.
Even an atheist can agree that a first cause, an original being, must have preceded the universe. This original cause or source is what so humbled Einstein, although he incorrectly described it as a religious experience. Faith is not the ability to imagine that which does not exist, but in finding relevance in that which is transcendent. To believe in G-d, then, means not that we are of the opinion that He exists, but that we have found relevance in Him. When a person says "I believe in G-d," what she or he really means is "G-d is significant in my life." For some people, G-d is relevant because they are concerned with the origins of existence. For others, G-d is relevant because they are concerned with the afterlife, and faith is a prerequisite for getting to heaven. Finally, for others, G-d is relevant because they believe that life has purpose.
The Jewish people's interest in G-d comes from the conviction that life has meaning. Why is a soul sent into the world to suffer in a physical body, for 80, 90 years? We know there is a purpose, that G-d is the author of that purpose, and we want to know and understand it. The mind is the soul's capacity to detect logic; the heart is the soul's capacity to respond negatively or positively. The respective functions of the mind, heart and soul are often confused. One who lives by his heart exclusively, trusts only what he feels. One who lives by his mind exclusively, trusts only what fits. However, neither of these tells us the truth. The mind demands that logic be trusted, the heart demands that the emotions be trusted. Yet, both can be mistaken. They do not reveal inherent truth. For that, we turn to the soul because the soul is a part of the Divine - and that is truth. When we have faith, when we find relevance in G-d, we are trusting that instinct in the soul that tells us that G-d is the purpose of life. In pragmatic terms, the mind, the heart and the soul must each fulfill their function. Where the mind is no longer adequate, the soul responds to truth. This is faith.
This is why in Chabad it is our approach to invite even one who claims not to believe - to do a mitzvah (commandment) before we engage them in a discussion on faith. Because in consideration of the existence of the soul, we just have to get them started, and with each mitzvah they do, their soul asserts itself more and questions become answered of themselves.
By way of analogy, if a woman's maternal instinct appears to be absent, you don't argue the philosophy of motherhood with her. Just put the baby in her lap and her maternal response will emerge.
Rabbi Konikov is director of Chabad of the Space and Treasure Coasts and can be reached at firstname.lastname@example.org.