The House of Bishops' background paper for the July 2024 meeting of the Church of England's General Synod, LLF: Moving Forward as One Church, is based on the belief articulated by Bishop Martyn Snow in the Preface, 'Unity matters - it really matters.' As the word 'one' in the paper's title indicates, what the bishops want is for the Church of England to remain united as one church, and they see the proposals contained in the paper as a way to achieve this. Unity and Truth is a critical theological review of what the bishops propose in their paper (which the General Synod very narrowly voted to support). What it shows is two things: Firstly, what the bishops are proposing as the way forward for the Church of England on the issue of human sexuality is not compatible with a proper theological understanding of what the unity of the Church requires. Secondly, should the Church of England continue to move in the direction that the bishops are proposing, conservative Christians in the Church of England will have no alternative, but to seek to establish an orthodox third province within the Church of England, precisely as a way to preserve as much unity as possible. This little book is an important resource for anyone wanting to understand why the way forward for the Church of England proposed by the bishops is theologically untenable and what a better approach would be like.