Producers were offered a conference room at the Emmanuel Centre in Westminster to unveil 'Voices of the Silenced', after the Vue Piccadilly cinema scrapped a reservation.
The film, which tells the stories of 15 people "emerging out of homosexual lifestyles", was made by the Core Issues Trust, a Christian group.
Speaking with Premier at the rearranged screening, the head of the Trust, Dr Mike Davidson said debate about sexuality is sometimes being shut down.
He said: "[People] talk about sexual fluidity and it's fine to speak of that in a transgender context, but we're not allowed to talk about someone who wants to leave [a] gay [lifestyle]."
Meanwhile, dozens of people demonstrated outside the Vue Piccadilly on Thursday evening against the cancellation of the movie's screening.
Andrea Williams, CEO of Christian Concern, a group which has been supporting the film, told Premier about the protest: "It was [peaceful], as we said it would be because we're peaceful people.
"It was a protest and we were there to make the point that we're not going away.
Referring to efforts to secure a venue for the 'Voices of the Silenced' premiere, Mrs Williams added: "There is a sense in which it has been exhausting in the past couple of days.
"What we were trying to build here was a community of people who would look at the film.
"What we know is that we need to hear those voices, we need to hear those stories."
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