Christianity not Mysterious was written in response to John Locke's
The Reasonableness of Christianity (1695). Toland asserted that there was nothing in religion that was above reason and that no Christian doctrine could properly be called mysterious. This book brought the controversies surrounding deism, atheism, and other forms of dissenting theological inquiry out into the open in quite a spectacular way. It attracted a very large number of replies and responses, and even in the late twentieth century some of his comments have not lost their power to shock, or at least to disconcert.
Browne's
Letter was easily the most popular reply to
Christianity not Mysterious. It is a famous answer to a famous book, and its immediacy as well as its revelations about the state of Irish Protestant attitudes towards deism or dissent at the end of the seventeenth century gave it a value that surpasses its actual content.
