The findings of the poll come amid renewed debate over whether public schools should teach ideas like "critical race theory".
The percentage of Americans possessing a biblical worldview also declines significantly.
ACN made a survey among American Catholics, showing that awareness of Christian persecution sees a major jump since a year ago.
Over ninety per cent of those who have five or more adult mentors say their life has meaning and purpose.
YouGov also found in another survey that 56% of Britons continue to regard the UK as a Christian country.
Among respondents, only 39 percent said they agreed with the statement: “human life is sacred.”