Sorry. It's all nonsense. We're Abraham's offspring based on our faith but the promises made to Israel don't apply to Christians. God said he wouldn't give Israel the diseases that he inflicted on the Egyptians. He also said that no one would be childless. That's obviously not true today.
We have no power to change our circumstances. You're a false teacher. Someday you'll receive a false teacher's reward if you don't repent.