Bishop Johannes was one of four bishops who were invited into the former South African president's home shortly after he died on Thursday aged 95.
His third wife Graca, as well as some of his children, and grandchildren, were all reportedly there to say goodbye.
Bishop Johannes told Premier's Des Busteed the family clearly appreciated the presence of the bishops at the house.
In the UK, MPs are paying tribute to Mandela during a special session in the House of Commons which will continue well into the night.
Speaker John Bercow made the opening address, followed by words from the Prime Minister.
David Cameron said: "Nelson Mandela was a towering figure in our lifetime; a pivotal figure in the history of South Africa and the world and it's right that we meet in this parliament to pay tribute to his character, his achievements and his legacy."
DUP MP Jeffrey Donaldson, who's a Christian and member of the British-South Africa All Party Parliamentary Group, is attending. Prior to the special session, he told Premier's Des Busteed during the News Hour why politians should reflect on all parts of his life.
South Africa is observing a series of commemorations over the next week, leading up to the state funeral on Sunday.
More than 100 current or former heads of state or government will attend the service or Tuesday's national memorial. The Prime Minister will fly to Johannesburg where he is among tens of thousands due at a stadium memorial service tomorrow. Following Tuesday's ceremony, Mandela's body will lie in state for three days at the Union Buildings in Pretoria, where he was inaugurated as President on May 10th, 1994.
A smaller number of international dignitaries, including Prince Charles, will attend the burial in the Eastern Cape village of Qunu, where the late president grew up. Mandela spent 27 years in jail before becoming South Africa's first black president in 1994. His administration replaced the racist white-minority regime that had enforced segregation of black and white people in a policy known as apartheid.
He went on to become one of the world's most respected statesmen.