Restored Relationships is speaking after research by the Trades Union Congress (TUC) found more than half of women have been sexually harassed at work - this figure going up to nearly two-thirds if the woman is aged between 18 and 24.
A quarter of women said they experienced unwanted touching at work while one in eight said someone tried to kiss them at work.
In nearly one in five cases, the sexual harassment came from a superior.
The vast majority of women - 79 per cent - did not report their harassment, often over fears they wouldn't be believed or would be less likely to receive a promotion.
The TUC has called the findings "shameful" and urged workplaces to improve.
Speaking on Premier's News Hour Peter Grant, from Restored Relationships, said: "We hear many stories that these kind of attitudes and this kind of behaviour is also prevalent in Christian organisations and in churches.
"I think very often we see a kind of casual sexism from the front of our churches, demeaning remarks about women and so on, that create an atmosphere which makes this kind of thing acceptable.
"It's something where the Church really needs to take action and to improve. It's the responsibility of women and also men to challenge this behaviour when they see it."
Listen to Premier's Antony Bushfield speaking to Peter Grant on the News Hour:
