A good question.............
"Religion is for people who are afraid of going to hell; spirituality is for those who have been there." (A member of Alcoholics Anonymous)
Perhaps just to get the ball rolling.............a quote from the book "The Spirituality of Imperfection"......
"What is spirituality? To have the answer is to have misunderstood the question. Truth, wisdom, goodness, beauty, the fragrance of a rose - all resemble spirituality in that they are intangible, ineffable realities. We may know them, but we can never grasp them with our hands or with our words..................And yet they exist; they ARE. Love exists, evil exists, beauty exists, spirituality exists. These are the realities that have always been recognised as defining human existence. We do not define them, they define us. When we attempt to "define" spirituality, we discover not its limits, but our own."
When the disciples of the Baal Shem Tov asked him how to know whether a celebrated scholar whom they proposed to visit was a true master, he answered......."Ask him to advise you what to do to keep unholy thoughts from disturbing you in your prayers and studies. If he gives you advice, than you know that he belongs to those who are of no account"
Oh yes!