How do we know the existence of the Devil is true?

Christian theology asserts the reality of the Devil based on numerous scriptural references that illustrate his character and actions as a malignant spiritual being. In addition to biblical texts, ancient historians such as Aristotle and Pliny provide insight into the cultural understanding of dragons and serpents, metaphorically linking them to the concept of evil personified in the Devil. Furthermore, the behaviors attributed to dragons, such as lurking in darkness and attacking the unsuspecting, parallel the ways in which the Devil operates, thereby demonstrating his presence and active role in opposition to God's creation and people.