'Throw your burden on Jehovah and he will sustain you.'

The faithful gather in Kingdom Halls striving to do the will of their maker. The hard-hitting drama Apostasy from former Jehovah's Witness Daniel Kokotajlo lifts the lid on what happens when real life situations fall outside those prescribed as 'acceptable' by their religion.

Does an almighty God really want to see people struggle and be 'disfellowshipped – the Jehovah's Witness' equivalent of excommunication – for not adhering to what seems to be arbitrary small print of not attending meetings or a point of disagreement with the leadership? What if a family member makes poor life decisions? Should they be cut off and treated like a stranger? How does a devout mother deal with being forbidden from supporting her wayward offspring?

This film gives an insiders' insight into life in the Jehovah's Witnesses. They don't celebrate birthdays, also off the menu are Easter and Christmas, which they view as 'pagan', and feminism is frowned upon as it is almost entirely controlled by male elders.

There are currently some 8 million Witnesses worldwide with close to 130,000 in the UK. They are convinced that the world as we know is will end in 'this generation'.

Apostasy as a film is a fascinating study in dogmatic belief and the fallout it can bring when teachings start to lose connection with the needs and lives of those who follow the faith – or those they live alongside. The huge pressure exerted by the leaders of the church on the congregation to turn up and meekly conform is, alas, something that can often be found in Christian evangelical churches also. What sets the Witnesses apart, though, is that for them attending meetings and carrying out duties is essential because 'God's love is conditional and must be earnt'. So, none of them know for sure if they've done enough to earn their place in the 'new system'.

Front and centre here is working mother Ivanna (Siobhan Downton Abbey Finneran) who is a committed Witness. She faithfully attends the meetings at her local Kingdom Hall along with her daughters Luisa (Sacha Parkinson) and Alex (Molly Wright).

The family drama plotline is framed against talk of how Armageddon is imminent. Things might be difficult now but soon all will be well when the 'new system' comes, heralding a heaven on earth for those who have secured their place through works.

Things begin to get strained when older daughter Luisa, starts questioning the strict rules about choosing meetings over her college lectures and hanging out with non-Witnesses – and not being keen to do her duty offering Watchtower magazines to strangers on the street.

Younger daughter Alex is much more on message, enthusiastically evangelising her friends, learning Urdu to help reach out to the local non-English-speaking community and willingly entertaining the notion of being paired off with an older and deeply uncool JW elder when he takes a shine to her. And this despite having had a blood transfusion at birth for her anaemia which is a 'sin' to Jehovah's Witnesses.

Things come to a head when Luisa gets serious about a boy outside the faith and ending up pregnant. This leads to a brutal disfellowshipping where she is no longer allowed to mix with the Witnesses or have anything other than minimal contact with her family.

With Ivanna in a painful position – the rules dictate she can have only minimal contact with her distraught daughter – it's a compelling buildup to a 'will she/won't she' do the right thing by her daughter climax.

The film is well made with exceptionally real and raw performances from the three female leads.

The writers might expose a lot of what appears to be negative about the Witnesses but Apostasy takes care to be somewhat balanced and doesn't mock their beliefs. Rather it leaves the viewers to make up their own minds about the faith.

The powerful underlying message however is that any form of fundamentalism which removes an individual's free will to care for those deemed 'lesser' or 'sinful' doesn't feel much like the service of a loving God.

Matt Adcock is head of communications for the Church Urban Fund. Follow him on Twitter @cleric20.