Are you looking for a general study on Irja' and its danger to Islam?

The meaning of Irja' (postponement) was previously discussed in Fatwa no. 34986. For further details, one may refer to books of creed that have addressed it, such as: "The Phenomenon of Irja' in Islamic Thought" by Dr. Safar Al-Hawali, "Nullifiers of Faith Related to Belief" by Dr. Muhammad ibn Abdullah Al-Dhahabi, and "The Simplified Encyclopedia of Contemporary Religions and Schools of Thought."