If people are determined not to believe something, then no amount of proof will change their mind. You will be called a liar for proclaiming things that call into question the way people are living. But remember, you’re just one in a long line of Cassandras and Jeremiahs — prophets who were scorned for being right. They stuck to their guns, and so should you. What’s the alternative? You can’t change the laws of nature.
If you still think you can overcome people’s aversion to the truth by uncovering better evidence, hey, go for it. Delve into the mysteries of geologic time, subatomic particles, or the outer reaches of the known universe, and bring the clearest evidence you can find — see if that makes any difference. Only those who have learned to listen will actually hear, and that depends in great measure on whatever chance circumstances shaped their upbringing; you have no control over it. Those who can’t hear are as good as dead — and therefore soon to rejoin the cosmic mystery in any case.
Some will say: How come God hasn’t sent some sort of obvious sign about this? And all you can say is, signs and miracles abound! Most people just don’t know how to read them. All creatures that move on the earth or fly through the air belong to communities equal in importance to your own. God doesn’t overlook anything, and we’re all in this together.
The foregoing is my own rough paraphrase of several verses from the Quran, 6:32-38, based primarily on the Ahmed Ali translation but with reference to several others on the Internet, especially for the crucial passage about the equal validity of non-human communities (other translations offer “societies” and even “peoples”). I even found a Sufi blog that interprets 6:38 as a call for animal rights.
Note however that in attempting to make this passage a bit more palatable for modern secular types, I have stripped out most of the poetry. The part about geologic time and subatomic particles, for example, paraphrases: “Seek out a tunnel (going deep) into the earth,/ or a ladder reaching out to the skies, and bring them a sign…” Fascinating stuff one way or the other, though, I thought. I am seriously exploring the idea of writing a modern bestiary now, and looking for inspiration. Who’d have thought the Muslim holy book would contain such a radically inclusive vision?