The widow of 7 July bomber Germaine Lindsay has spoken publicly for the first time, condemning his "abhorrent" Tube attack that killed 26 people.
Ms Lewthwaite believes mosque visits affected her husband's mind
Samantha Lewthwaite, 21, has since given birth to a daughter by Lindsay.
She told the Sun she wanted to remember the man she loved, but added: "The day will come when I'll have to tell [our children] what he did."
Trips to radical mosques had "poisoned" the "innocent, naive and simple" 19-year-old's mind, Ms Lewthwaite said.
The couple had married in 2002, before moving from Huddersfield, West Yorkshire, to Aylesbury, Buckinghamshire.
But Lindsay turned from a "peaceful man who loved people" into someone whose character she did not recognise, after meeting a group of men at a prayer meeting last year, she told the newspaper.
She said he began disappearing for days at a time, visiting mosques around the country.
"How these people could have turned him and poisoned his mind is dreadful," she told the Sun.
"He was an innocent, naive and simple man. I suppose he must have been an ideal candidate."
She assumed Lindsay was at a mosque on 7 July, when he detonated the day's most devastating bomb on a Piccadilly Line train near Russell Square.
"I saw the images on TV and got very upset," she said.
"I was crying when I saw people looking for family members. Obviously I didn't know then I was linked to what I was seeing."
Ms Lewthwaite, who is the daughter of a British soldier, reported her husband missing following the attacks.
Her "world collapsed" when police later showed her CCTV footage of him on his way to carrying out his attack, she said.
"What on earth had changed so much so quickly to turn him from loving husband and father to a man who could carry a bomb on to a Tube train and kill."
The 7 July bombings killed 56 people, including the four bombers.
Ms Lewthwaite said she believed her partner could not have left without saying farewell to their 17-month-old son Abdullah.
She told the paper she thought she heard him on the stairs of their home.
"He kissed our child goodbye and then crept off to blow up King's Cross.
"In the morning I found he'd left the keys on a table downstairs. He obviously had no more use for them," she told the newspaper.
Ms Lewthwaite was speaking to the Sun 15 days after giving birth to daughter Ruqayyah.
The chairman of the Muslim Council of Britain's mosque and community affairs committee, Ibrahim Mogra, told BBC Radio Five Live he was concerned by what he called Ms Lewthwaite's "generalisation" about the mosques.
Mr Mogra said her comments covered hundreds of mosques but if she could identify the ones her husband had visited, they would be "looked into".
"We know for a fact and this is acknowledged by the government that the majority of the mosques in our country preach the message of peace, of harmony, of living with everybody in peace and looking after your neighbours," he said.