Auckland District RSAs President Graham Gibson and world-renowned opera star Simon O'Neill stand shoulder-to-shoulder in support of the plan.
Graham Gibson said "not only does this building remember those that went overseas and didn't return, it will also serve as a living memorial for those young New Zealanders who continue to serve overseas."
Simon O'Neill, who has performed at the Royal Opera House in London's Covent Garden, said the church building was made for music and uplifting the human spirit.
"The atmosphere, acoustics and scale of St David's create an incredibly valuable opportunity for music in New Zealand. Its location in Auckland - Unesco City of Music – is fitting."
Simon and wife Carmel Walsh-O'Neill are founding patrons of The St David's Centre for Music.