Maureen Greaves, the widow of murdered church organist Alan Greaves, has spoken of the "evil" that led to his death.
She also said she has gained comfort from her faith in her grief.
Hear her address to the congregation at St Saviour's Church:
More top news
The huge counter-terrorism effort is placing an unsustainable strain on wider policing service, one of the most senior officers has warned.
A man and woman have been arrested on suspicion of murder after a badly burned body was found in a garden in Southfields, south-west London.
Kim Jong-un has called Donald Trump "deranged" and says he will "pay dearly" for his threats, according to North Korea's state news agency.