How do I help prevent human extinction here on earth?

Spreading wisdom and kindness is the first step of many.
If you look at religions everything in any religion that is not about wisdom and kindness you will often find is only a way for ministers and priests to have money to live or take vacations. This is observable if you are logical and reasonable in your lives.
There for "Guilt" in any religion is ONLY about you giving money to them instead of yourselves.

It's a lot like a parent who forces their children to be "financial slaves" the rest of their lives who work only to support their parents so their parents can have a good life but the kids go through hell in the process.

So, Spreading wisdom and kindness not specifically attached to any one religion can be helpful because the biggest religions all want to kill each other either directly or indirectly. Why?

It's mostly about power, money and control of the people and their actions. Religions enslave the masses and are the opiate of the people. In other words religions are drugs to the people who believe in them.

But, isn't a religion a better drug than actual drugs?

Sometimes. But, what happens when religious people get so attached to their religions that they put down or kill others who aren't members of their religions?
For example, ISIS and Al Qaeda are often drug addicts who have chosen the drug of ISIS and Al Qaeda rather than actual drugs and this is a part of the actual problem we face today.

These are the most blatant examples of the problem of all religions we have now that we face on earth every single day.

Mao Tse Tung's statement was "Religion is poison". But, I would say in some ways drugs and religion are both poison, but at times Communism and Capitalism are poisons too and I think we must consider them to be religions too. Democracy is also a religion.

Capitalism CAN be a very good thing. It is a way to harness "Selfishness" for the good of all or most of the people since Communism and socialism don't work very well or not at all because "Selfishness" destroys them both. But, in China and the U.S. and Europe now we see the Evils also now of Capitalism being incredibly selfish just as it was in 1929 before the big stock market Crash that caused The Great Depression WorldWide and World War II, The Korean War and to some degree even the Viet Nam WAr.

But, I digress. So, how can I help prevent human extinction here on earth? Ask yourself this. If you are intelligent enough to actually get what I'm saying here. Then the world needs you to stay alive and help the human race not go extinct.

Spread first Wisdom and kindness. Then stay alive to figure out how you can help yourselves and others survive whatever comes.

Because if you are intelligent enough to actually understand what I'm writing here, the world needs you or we all will go extinct. If you are a Free Thinker you may be the one who figures out the way  the human race doesn't go extinct during the next 500 years here on earth.

By God's Grace