Which of following statement differentiates the obsessional idea from delusions?

An obsession is a recurrent and persistent thought that is experienced by the patient as intrusive and inappropriate. It causes marked anxiety and distress in the patient. Delusions are fixed false belief that are not widely held within the context of the individual's cultural or religious group. These beliefs persist even with presence of a contradictory evidence. Common types of delusions are: Delusions of control Delusions of grandiosity Delusions of guilt Delusions of reference Persecutory delusions Somatic delusions Thought inseion, withdrawal, or broadcasting Ref: 100 Questions & Answers About Your Child's Obsessive Compulsive Disorder By Josiane Cobe page 33, Meltzer H.Y., Bobo W.V., Heckers S.H., Fatemi H.S. (2008). Chapter 16. Schizophrenia.