Here is some advice to a person who has decided for whatever reason that he cannot believe in a god of any kind. This actually includes myself, so I may be biased here. Such a person may be called an atheist, an agnostic, or a secular humanist. For the sake of simplicity, I will lump all of them together under the Humanist label.

• Do not assume that because you have rejected theism that most people who accept a theistic religion are stupid. They may indeed have a different spiritual orientation than you. Respect them anyway, just as you would want them to respect you.
• One of the worst things you can do to damage your credibility is to only care about the rights and dignity of your fellow non-theists and ignore everyone else.  Stand up and defend the rights and dignity of ALL religious people too, including Jews, Muslims, Christians, and others.
• Just because you are non-theist does not mean that all other non-theists should be embraced. If a famous non-theist is known to be a racist, have committed acts of sexual abuse, or has committed theft or murder, reject him.
• It is  true that people of various religions have committed atrocities against outsiders. But so have non-theists who followed an extremist ideology, like Communism. It is DOGMA that kills people, not religion.
• You can find fellowship in the following organizations:  the American Humanist Association (https://americanhumanist.org/), or the UU Humanist Association (http://huumanists.org/). Also read this:
  

  Humanist Voices in Unitarian Universalism

  

In short, don’t be like Madalyn Murray O’Hair, the founder of American Atheists. Or Ayn Rand, the founder of Objectivism. Those two arrogant, bigoted extremists brought disgrace to atheism in America that is still a problem to this day. I wish neither of them had ever existed.