I assume that your preaching was based on your understanding of God's word. And the lady berated you based on her understanding of God's word. What I don't understand is why God doesn't provide the same understanding to everyone? That shouldn't be difficult for an all-knowing, all-powerful deity. And should be essential for an all-loving one. Not to do so would seem to be dereliction of duty. The usual answer is that God has given us free will, but that isn't an argument as guidance about what is right doesn't interfere with our free will to go against that guidance.