What is the meaning of the following quote: "It is only in the heart that one can see rightly, what is essensial is invisible to the eye".

The quote is talking about the inability of most adults to be able to believe in things that they cannot see with their eyes. By the time we have reached adulthood, we have lost that child-like quality that allows us to imagine what can't be proven. As adults, we see only the outward appearances of people and things. We no longer see a person's inner beauty, for example, or appreciate the beautiful things in nature. As adults, we have become cynical and have lost our child-like innocence. We concern ourselves with the daily, "serious" subjects of life, such as paying bills, getting a better job, or buying a bigger, better car. The love we feel for other people in our lives is not something we can see, but we know that it's there because we feel it within our hearts. The differences between our childhood and our adulthood are vast. As a child, we use our imaginations and feel wonder at such small things that most of us as adults don't see anymore. The child can see the magic in the world and believe in it. Unfortunately, most of us lose that by the time we have become adults.