Consider the way you would react if a Hindu began quoting from The Bhagavad Gita or the Vedas to convince you he was right? Would you appreciate being witnessed to about his belief in Brahman and being called 'foolish' or 'damned' for mocking his Gods?
From what I know about hindu scriptures, nowhere are people that reject Krishna described as being fools for rejecting the gods of hinduism.
As far as being called "foolish" or "Damned" I've been called much worse. You just have to take it on the chin and turn the other cheek!
I can take on board people's reluctance to receive Biblical instruction, however if we want the knowledge of Jesus Christ we can only go to the Jewish Bible and Christian New Testament. I used to be the same.
Whatever we seek to teach, we cannot escape the fact that we need to study authorities on the subject.
Want to teach car mechanics we need to study the manuals. No point studying and reading about fly fishing!
I wouldn't trust a plumber to give me a heart by-pass operation.
Drivers have to respect the rules of the road, and what's more we take on board the instruction our driving instructors give us!