I would have never thought about being "too spiritual" until I read some excerpts from Dark Night of the Soul, written by John of the Cross, a a sixteenth-century Carmelite friar and priest.
If we're not careful, our spirituality can go in the wrong direction. John wrote that it often takes a dark night of the soul to uproot spiritual sins. Spiritual sins? Yes, spiritual sins. Often, the religious leaders in Jesus' time were guilty of such sins. The Pharisees could be a judgmental bunch, and it was these men who Jesus often rebuked for their self-righteousness.
It's important as believers that we don't take on a Pharisaical attitude.
Four out of the seven spiritual sins that John of the Cross described caught my eye (and my heart).
Secret Pride: When we want others to notice our spirituality by our spiritual exercises or practices.
Spiritual Greed: when we're not satisfied with what God does for us, and we are more caught up with the emotions a devotional life give us.
Spiritual Wrath: when we become bitter when the benefits of the spiritual life are taken away.
Spiritual Gluttony: when we pass beyond the limits of moderation and nearly kill ourselves with spiritual exercises.
John of the Cross described how God takes away our vices in the dark night, only to create virtues within us. “Through the dark night pride becomes humility, greed becomes simplicity, wrath becomes contentment, luxury becomes peace, gluttony becomes moderation, envy becomes joy, and sloth becomes strength.”