Churches should be among the first to include, welcome and support transgender people, according to one of the UK's leading evangelical Christians.

In his new e-book published today, the founder of the London church and international charity Oasis, Rev Steve Chalke, highlights that in the New Testament, the first non-Jewish convert to Christianity was someone with sexual and gender minority status.

In 2013, Chalke became the world's first prominent evangelical Christian to declare publicly his support for same-sex relationships, to the dismay of some conservatives.

His new book, The Gender Agenda: Towards a Biblical Theology on Gender Identity, Reassignment and Confirmation, is an attempt to 'heal the hurts' inflicted on people who are transgender and help Christians form an inclusive theology which the author argues is both Christ-like and biblical.

Chalke said: 'There are some within the Church who loudly proclaim their opposition to the "sin" of transgender expression, let alone of transition, whilst other more nuanced responses, which begin with tones of pastoral concern, only later reveal that they too are playing the same "traditional" binary tune.

'The subtle shift from viewing transgender people as "depraved sinners" to "unfortunate victims of psychological pressures and mental illness" camouflages the fact that, in the end, as numbers of trans people have learned to their cost, the environment it creates is just as toxic for them.

'I am convinced that the standard we are called to advocate beyond all others is that of grace; of God's radical inclusion as most clearly demonstrated through Christ. Put simply, our task is to be the indisputable proof that God is love – and that, to the extent in which we fail, we model, quite literally, "dis-grace".'

The book argues that the theme of inclusion is consistent throughout the Bible, most notably in the ministry of Jesus who reached out to people ostracised by the society and religious authorities of the day.

But it also proceeds to illustrate a specific example in the book of Acts in which Philip, a leader of the early Church, baptises an Ethiopian eunuch even though Jewish theology would not then have deemed him worthy of it due to his status as a foreigner and a eunuch.

Chalke continued: 'For the record, I am not suggesting that a 1st century eunuch is the exact equivalent of a 21st century trans or intersex person. In my experience, some trans people find it a helpful analogy, whilst others don't see it that way because the story doesn't really go to the question of gender identity as such. It is, however, an extraordinary example of the early Church's understanding of the principle of radical inclusion as central to their mission and purpose.

'The point is this. Before the theological questions have even been surfaced – let alone been debated and resolved – Philip goes out on a limb. Why? Finding himself in this unprecedented situation, he can only be guided by his understanding of the teaching and example of Jesus – through the inspiration of the Holy Spirit – as he understands it and as the text makes plain.'

The book also provides an overview of what it can mean to be transgender and the hurt, pain and mental health damage that can arise when people feel they have to suppress what they see as their true gender identity.

For more information and to download a copy of the e-book, click here.