Humanity's biggest mistake is the inability to simply not care about what other people think, believe or, sometimes, do. We meddle to try and force others to think as we do because we alwas assume our own views are the right ones.
Its biggest weakness is our inability to exist with synergy with our own world.
Actually there is. God who made heaven and earth established the ten commandments which tells us what is right and what is wrong.
God also says through the bible:
"You shall not round off the side-growth of your heads nor harm the edges of your beard."
Leviticus 19:27
So no round off haircuts or trimmed or cut beards. Those are wrong.
"You shall not make any cuts in your body for the dead nor make any tattoo marks on yourselves: I am the Lord."
Leviticus 19:28
Tatoos are bad.
"You are to keep My statutes. You shall not breed together two kinds of your cattle; you shall not sow your field with two kinds of seed, nor wear a garment upon you of two kinds of material mixed together."
Leviticus 19:19
Darn, jeans and polyester together = sin. God dam!
"Likewise, I want women to adorn themselves with proper clothing, modestly and discreetly, not with braided hair and gold or pearls or costly garments."
Timothy 2:9
Oh no he didn't. All bishops and priests, all clergimen...they are all doing bad things!!!!
While I do think some of the aspects of the commandments might be good and correct things to abide to (like, no killing, no stealing...and thats about it I guess), the whole "god says what is right or wrong thing" is too mid 1500's. We, as humanity, have grown past that. And right and wrong evolves as humanity does. So, he is right in the sense that there is no real right or wrong, only a matter of opinion and context. What is right for me is wrong for you and vice versa. But that means nothing. There are core truths for most people but they will never be translated across every single individual.