Hypocrisy is found in various aspects of life, whether in religion, politics, or social parts. Hence, some of the church's hypocrisy is an outcome of different ups and downs in life. Starting with the problem in the novel, some of the hypocritical pastors engaged in an immense role in affecting the folk's lives because they persuaded people that God ordered them to do so. To accomplish their personal interests, the abusive monks disguise their verbal speech, smiles, and fine clothes like mild sheep to delusional followers, leaving them with guilt, shame, and spiritual scars. The present study aims to examine the hypocrisy and heresy of the church as portrayed in Okezie Nwoka's novel entitled God of Mercy. It reflects the source of corruption and heresy in some churches in a way that the corrupted priest adopts different brainwashing strategies to deceive their victims. Furthermore, the false priests are trying to force their doctrine on their cults. In the current study, the researcher relied on the Marxism theory to analyze the novel, the theory concentrates on Karl Marx's ideas of superstructure and base and how false religion can be used as a dangerous weapon by hypocrites and avid priests. The findings of the study revealed that hypocrisy and heresy were well portrayed in the Okezie Nwoka novel. It depicted how religion and priests do not always serve God's call. The author presented religion as a dangerous weapon and the victims reached their downfall by following a twisted offender. The fraud monks were pictured as caring only about themselves, their reputation, and their wealth. Also, they intended to follow false doctrine and quote unbiblical phrases to maintain their prosperity.