It is hoped the blaze has not caused any major structural damage.
Smoke damage to the interior of the church, however, is ‘colossal,’ the vicar of Antrim, Archdeacon Stephen McBride, has said.
A GoFundMe page has been set up to raise funds to repair the historic church.
The fire was discovered on Friday December 27 when one of the parish flower arrangers went into the building to put in some flowers for the Sunday services.
Archdeacon McBride said: “When she opened the door she was met with the smell of smoke. On opening the inner doors, she discovered that the church was filled with dense smoke.
“Thankfully she did not attempt to enter the building, but phoned for the Fire Service who were at the church within minutes.”
Archdeacon McBride said it is thought that one of the candles at the Massereene Chapel reignited after the Christmas morning service, although the church is awaiting a report from the Fire Service to verify this.
Due to the doors being closed, the fire was starved of oxygen and burned itself out.
“The damage is very localised and we are hopeful there is no major structural damage, but will await an architect’s closer inspection,” Archdeacon McBride said.
“However, the smoke damage is colossal. The smoke even managed to get inside cupboards that were shut.
“Having just celebrated Christmas with some very uplifting services and also being featured recently on UTV’s Hidden Places Northern Ireland, it is so sad to now look at our church building in such a terrible state.”
The Bishop of Connor, the Rt Rev George Davison, has visited All Saints’, and was joined by the Mayor and Mayoress of Antrim and Newtownabbey, Councillor Neill Kelly and his wife Christine. Archbishop John McDowell, who served his curacy in Antrim Parish, hopes to visit later in the week.
The archdeacon said the parish had also been delighted to welcome local MP Robin Swann to the service held in the Parish Centre on the Sunday after the fire.
Archdeacon McBride commented: “When Robin came in through the door on Sunday morning and hugged me, it is a moment I will never forget.”
He added: “The messages of support have been so encouraging and uplifting and help ease our pain.”