It would benefit the organization to encourage frugality and responsible money management, since that would leave most people with some disposable income that could be donated to the cause. I think they have long since learned not to specifically promote the idea of assuming that their futures are assured by the closeness of Armageddon.
I guess it's a bit of a conundrum- if you advise the rank and file to prepare for a future in the present system of things, they may lose the urgency that comes from the "sooner than you think" message. But a following that places little value on financial success and long-term planning will find itself unprepared when they are of retirement age. And then they have less to put in the coffers.