A total of 205,100 sampled addresses were mailed survey invitations. Respondents were given a choice to complete the survey online, by mail, or by calling a toll-free number and completing the survey over the phone with an interviewer. Of the 36,908 U.S. adults who completed the survey, 25,250 did so online, 10,733 did so by mail, and 925 did so by phone.
It goes on to say the results were then weighted to get a representative demographic sample, e.g. if more older people answered, younger responders would count for more.
https://www.pewresearch.org/religion/2025/02/26/religious-landscape-study-methodology/
It goes on to say the results were then weighted to get a representative demographic sample, e.g. if more older people answered, younger responders would count for more.
I can tell you right now that there is a vast majority of people that are too poor or too scared to participate for any of this to be accurate.