Did God told in the passage you must use pesticide and other harmfull chemicals to grow plants or tree bearing fruits?

Did he say we can't?

Did God also said in the passage embalm the fruits prior shipment? did you not know the best full nutrients a fruits can give is when you directly pick them from trees and eat them?

When did he say not to? Yes I did know that, but how would you propose every person on the planet grows their own food so they can DO that?

Why did you think most people do prepared to eat organically grown products? especially those who new about cancer as a symptom like fever?

This is unintelligible

Can your math professor go beyond the standard or constants defined or found by science, like speed of light?

what is the point of this question?

Isn't science postulate a theory then proved according to the empirical, testable laws of science? going back to your professor, did they for the fact experimented, tested and proved the mathematical laws? or are they not using books to teach students?

Are they not preaching then?

We established the definition of preaching, if you prefer to call it that, fine. But it isn't a religion. There are no 'temples' where people come to worship, no prayers, only science and research.