Everyone may have heard about Masons, but very few people have actually learned anything at all about Freemasonry.
There are no Masonic churches, but there are certainly Masonic buildings, Temples and Lodges in most towns.
We're not a secret organization, we're a Fraternity that can be found on the internet, in the phone book, and by looking for the big building that with the Square and Compasses on it. If we were a secret organization, we'd suck at it after advertising where we are, when we meet, and how to contact us.
Freemasonry makes good men better. We support and participate in our communities. We are the largest and oldest fraternity and charitable institution in the world. If you want to know more about what Freemasons do, go to your local Lodge and ask.
If you went and sat down in a masons church ... you'd be the only one there; we don't have churches. If you went and sat down in a Masonic Lodge ... well, it depends. If it was a public event, you'd be welcomed (and probably fed. We're big on food). If it were a private or business meeting, you'd be politely asked to leave. Just like you'd be asked to leave a shareholder's meeting if you weren't a shareholder in that company.
If you want to become a Mason, you ask to join.
If you've heard 'theories' about the number of president that were masons ... well, you've been listening in the wrong places. The Presidents who were Freemasons were: George Washington, James Monroe, Andrew Jackson, James Polk, James Buchanan, Andrew Johnson, James Garfield, William McKinley, Theodore Roosevelt, William Taft, Warren Harding, Franklin Delano Roosevelt, Harry S. Truman, Gerald R. Ford, and Lyndon Johnson.
I'm a Freemason.