If you’re really dealing with an agnostic, someone who might in principle be open to dealing with God and who is only upset with the existing religious structures she has seen, that’s quite different from the militant atheist who comes after your religious faith with both barrels. It wasn’t always clear what Ayn Rand really believed, but she often painted religious faith as some kind of mindless altruism, which it isn’t. And it cannot be, if God is real.
I agree God is very real. I wouldn’t be alive without Him. However Ayn Rand can believe as she wishes.