Thatcher was now at peace after "a life led in the heat of political controversy," the Right Rev. Richard Chartres said during in his funeral sermon at St. Paul's Cathedral.
Chartres also paid tribute to her forthright character, Methodist upbringing and the compassion she showed others, the BBC reported in its blog of the service.
Queen Elizabeth II was among the more than 2,000 British and world dignitaries who attended the funeral.
"We come to this cathedral today to remember before God Margaret Hilda Thatcher, to give thanks for her life and work, and to commend her into God's hands," the Very Rev. David Ison, the dean of St. Paul's Cathedral, read in the bidding prayer. "We recall with great gratitude her leadership of this nation, her courage, her steadfastness and her resolve to accomplish what she believed to be right for the common good. We remember the values by which she lived, the ideals she embraced, her dignity, her diligence, her courtesy, and her personal concern for the well-being of individuals."
Thatcher, Britain's only female prime minister who served from 1979 to 1990, died April 8 April after a stroke. She was 87.
In his address, Chartres recalled the hurdles Thatcher, a Conservative, overcame as she rose to power. He noted only 4 percent of the members of Parliament were women and that people were prejudiced against her because, among other things, she was a woman and a mother.
But Thatcher became a symbolic figure, "even an 'ism,'" Chartres said. But she also "is one of us, subject to the common destiny of all human beings."
Chartres said there is a "legitimate place" to debate Thatcher's legacy, but Monday's funeral service wasn't it.
Earlier the longest-serving British prime minister in modern times left Parliament for the final time as a hearse took her body from the crypt chapel in Westminster Palace to the start of the military procession at St. Clement Danes.
Protesters dotted the funeral route. At Ludgate Circus, protesters turned their backs on the procession, some chanting, "What a waste of money" and "Tory scum," The Guardian reported.
Police arrested three men for graffiti newly sprayed near St. Paul's Cathedral.
"Three men were arrested on suspicion of criminal damage and being in possession of articles likely to be used to commit criminal damage," police said in a statement. "The three men were taken to a central London police station and remain in custody."
The funeral marked the end of a 10-day mourning period for Thatcher, described by Cameron as the woman who "rescued our country from postwar decline."
The gun carriage bearing Thatcher's coffin, the bearer party and the escort party were led by a band of the Royal Marines, The Guardian said. A light drizzle greeted people standing along the procession route.
Thatcher supporter Michael Barton, 70, compared Thatcher to Winston Churchill, noting they both were wartime leaders and commenting that he believed her reputation "will only rise as the decades ... pass," The Guardian reported.
"She was an amazing person -- a woman from a working class background who took on the toffs," Barton said from his spot in Parliament Square. "She rocked the boat something rotten and good for her for doing it. I'll miss her and I'm very sad."