Here's a small Baha'i compilation that might be of interest, all from 'Abdu'l-Baha, a Baha'i philosopher and son of Baha'u'llah, the Manifestation of God.
"As to the question of evil spirits, demons and monsters, any references made to them in the Holy Books have symbolic meaning. What is currently known among the public is but sheer superstition."
"The reality underlying this question is that the evil spirit, Satan or whatever is interpreted as evil, refers to the lower nature in man. This baser nature is symbolized in various ways. In man there are two expressions: One is the expression of nature; the other the expression of the spiritual realm. The world of nature is defective. Look at it clearly, casting aside all superstition and imagination... God has never created an evil spirit; all such ideas and nomenclature are symbols expressing the mere human or earthly nature of man. It is an essential condition of the soil of earth that thorns, weeds and fruitless trees may grow from it. Relatively speaking, this is evil; it is simply the lower state and baser product of nature."
"There are no earth-bound souls. When the souls that are not good die they go entirely away from this earth and so cannot influence anyone. They are spiritually dead. Their thoughts can have influence only when they are alive on the earth... But the good souls are given eternal life and sometimes God permits their thoughts to reach the earth to help the people."
"There is no power exercised over the people by those evil souls that have passed away. Good is stronger than evil and even when alive they had very little power. How much less have they after they are dead, and besides they are nowhere near this planet."