""Mammon or Covetousness: The Sin of the Christian Church and the Witnessing Church: A Sermon"" is a religious text written by John Harris and published in 1839. The book discusses the sin of covetousness, or the excessive desire for wealth or material possessions, and how it has affected the Christian church. Harris argues that the pursuit of wealth and material gain has led to a lack of focus on spiritual matters and a neglect of the needs of the...