Tori Johnson to be mourned at church near Martin Place

THIS is the church where thousands of Sydneysiders will pay their final respects to Sydney siege victim Tori Johnson, just metres from where he was killed on Tuesday.

Mr Johnson's family will hold a special memorial service at St Stephen's Uniting Church on Macquarie St Tuesday - one week to the day after his life was tragically cut short at the hands of a deranged gunman.

Prominent Uniting Church minister Reverend Bill Crews will lead the service from 11am.

He was among the religious leaders - including Rabbis Levi Wolff and Zalmen Kastel, Sheikh Wesam Charkawi and Hindu priest Pandit Ramachandra - who accompanied Tori's father, Ken Johnson, as he visited the impromptu floral memorial which has engulfed Martin Place.

Rev. Crews issued a video Christmas message on Twitter today, calling for hope in the face of recent days' tragedies.

"It's no wonder we are looking towards Christmas in a pretty dark, confused, worried state of mind," he said.

"If we really listen to the Christmas story, we hear that when the world is in its darkest moments, in the most unlikely place and in the most unlikely way, new hope is being born.

"My message to you is clear: reach out beyond yourself, share the Christmas spirit with others and spread light around the world."

St Stephen's Uniting Church Council chair Rosalie Ramsay said special arrangements had been made to ensure the maximum number of mourners could farewell Mr Johnson on Tuesday.

"It is a lovely setting, a beautiful church with plenty of room for people who come in," she said.

"We also have closed-circuit TV downstairs in case we need to broadcast down there from the hall."