It took the Omagh Crown Court jury of six men and six women four and a half hours over two days to unanimously convict the former provincial superior of the Society of Missionaries of Africa, or White Fathers as better known, based at Cypress Grove House, Templelogue in Dublin.
The 76-year-old disgraced pensioner priest, who had dismissed the abuse claims as "absolute rubbish ... they never happened", showed no emotion, never once looking up, head bowed all the time as he palmed a set of rosary beads in the dock.
By their verdicts the jury accepted that Fr Lewis was a vile evil paedophile who preyed on the Co Fermanagh sisters after befriending their parents nearly 50 years ago.
By their verdicts they also rejected the picture painted by his defence, backed by testimonies from around the world, including an African Bishop, that he was simply a loving caring wonderful man of God.
In all, following his six week trial, he was convicted of a total of 11 counts of indecently assaulting the three sisters when they were youngsters, separately and on differing dates between August 1963 and September 1973.
What the jury did not return verdicts on was a claim by one sister that he raped her, not once but twice, in the White Fathers' house in Dublin, and a claim by a fourth sister that she was sexually abused at the Order's former home in Blacklion, on the Fermanagh Cavan border.
They were not the subject of charges as these alleged crimes were said to have been committed in the Irish Republic, and thereby outside the jurisdiction of the North.
However, from the start the jury heard of these alleged brutal sex attacks from prosecuting QC Ken McMahon who said the priest had wormed his way into the family through a fellow, but innocent cleric.
Mr McMahon had told the jury that although welcomed into their home at anytime, he often chose to call at bedtime or on Saturday bath night.
The lawyer further claimed that Fr Lewis, his actions hidden by a large kitchen table, managed to abuse one of the girls in front of her father, who was unaware of what he was doing.
The girl, now a grown woman, later told the court that Fr Lewis also abused her while telling her and her sisters bedtime stories in their darkened bedroom.
However, when she was aged 21, the priest raped her in the Templeogue base of the White Fathers after her parents sent her to him when they discovered she had an affair with a married policeman.
The court heard, she did not shout or scream; she was traumatised, and that he raped her again the following night, despite her begging him to stop.
She later complained to her mother about the abuse, although said nothing of the rapes, and it was not until two years ago that she finally went to the police, both north and south.
Her sisters, one of whom had actually initially "forgiven him", also told the police of the abuse they suffered at the hands of the shamed cleric.
The priest, who swore to police and the jury he "never touched those children", will be sentenced next month once pre-sentence reports are completed.