Guided tours will be offered of the sprawling complex, featuring what is said to be New Zealand's biggest permanent LED wall, a 24-metre-wide screen which arrived from China last week to form the backdrop for the main 864-seat auditorium.
Giant photographs of founders Bishop Brian Tamaki and his wife Hannah hang in several public spaces in between a school with 170 students, an early childhood centre for 70, a gym, a recording studio and function rooms.
From outside, the building still looks like a factory. The most conspicuous sign is a giant billboard for the SuperCity gym operated by the Tamakis' son-in-law Kaine Warren, which provides boxing training for local youths on a donation basis and boasts adult fees as low as $12 a week.
Inside, piles of insulation and other building materials were still waiting to be installed yesterday afternoon. Spokeswoman Anne Williamson said volunteers would be working through the night to complete construction in time for a banquet tonight marking the Tamakis' 30 years in the ministry.
"Electricians, welders and builders, my husband included, will turn up after work tonight and will work through until probably 12 o'clock."
The church has funded the new complex by selling its previous base in Mt Wellington, valued at $4.9 million, and by asking each family in the church to donate $1000.
Membership has been reported to be dwindling. Accounts filed with the Charities Office show that donations to the Auckland church declined from $2.1 million in 2008 to $1.7 million in 2012.
Churches have closed in Kaitaia, Thames, Te Puke, Gisborne, Taumarunui, Wanganui and Porirua.
Eight MPs including Maori Affairs Minister Pita Sharples, NZ First leader Winston Peters and Internet Mana leader Hone Harawira are among guests expected at the official opening tomorrow night.
City of God opens
• The building: Destiny Church headquarters
• The event: Free concert with Stan Walker, bouncy castle and children's entertainment, free food stalls
• The address: 25 Druces Rd, Wiri
• The date: Sat May 31, 10am-5pm