Even though we cannot see them, evil spirit creatures do exist. The Bible relates that an invisible spirit person used a serpent, much as a ventriloquist uses a dummy, to communicate with the first woman, Eve, and led her to rebel against God.
हम, दुष्टात्माओं को देख नहीं सकते, मगर वे अस्तित्त्व में हैं ज़रूर ।