A 56-year-old former Jehovah's Witness will spend two months in jail with the rest of the sentence suspended, and undergo community service, over historical offences relating to the inappropriate touching of two girls.

The ACT Magistrates Court heard the man was at the house of fellow Jehovah's Witnesses in 2004 when the then-43-year-old asked the couple's 14-year-old daughter to log on to the computer for him.

As she was typing the man put his hand on her bottom, resting it there for a number of seconds.

In a separate incident the girl and her 12-year-old sister stayed at the man's house when his wife offered to look after them so their parents could celebrate their anniversary.

The girls slept the night at the man's house and after breakfast the next morning he asked the 12-year-old girl to sit on his lap.

When she did not respond he picked her up and placed her on his lap, hugging her tightly.

He then placed his hand inside the girl's underwear, leaving it there for two or three minutes.

The court heard the girl froze with fear, until she summoned enough courage to say she needed to use the toilet and left the room crying.

Sisters became estranged for 10 years

The prosecutor read victim impact statements to the court outlining the trauma the incidents had caused the girls.

The 14-year-old, now an adult and married, stated as a child she was full of confidence, ambition and had drive to succeed.

But she said this changed when the man violated her and her sister.

She said she had been estranged from her sister for 10 years because the incident left her feeling helpless and powerless and every time she saw her sister it reminded her that she could not protect her.

The statement read to the court also described how the woman still found it difficult to look at children and would sometimes shake and vomit uncontrollably.

The court heard she had also suffered because she had wanted to be a mother but is on medication to help her sleep and that medication would make it dangerous to have a child.

The woman's younger sister also wrote a statement describing the regular emotional breakdowns she still suffers, as well as flashbacks of the trauma.

In the statement she said she had low self-esteem and felt disconnected from her family.

Church didn't report matter to police when informed

The court heard the girls' parents had informed the church at the time, which conducted an internal investigation, removed the man from the community and the man wrote a letter of apology to the family.

The matter was reported to police in 2015.

The man's lawyer told the court the man had since lost his security clearance, was expected to lose his public service job within the coming weeks and had gone through a marriage breakdown.

In sentencing, Magistrate Bernadette Boss told the court the man was in a position of trust and in the matter of the 12-year-old girl being in his home, that she should have been able to feel safe and protected in the absence of her parents.

Magistrate Boss said that it was most unfortunate a church was again involved and failed to inform the authorities, making them complicit in the matter, exacerbating the effect on the victims.

The man was given 200 hours of community service and a two-year good behaviour order for the offence against the eldest girl.

He was given a nine-month jail sentence, of which he will serve two months in full-time custody with the rest suspended, for the offence on the 12-year-old girl, as well as a second two-year good behaviour order.

He will also take part in the sexual offenders program.