The level of irreligion in America depends on how you measure it. And the vitality of faith in America is much more than simply how people label themselves.
Barna Group tracks the following 15 metrics related to faith, which speak to the lack of Christian identity, belief and practice.
Post-Christian = meet at least 60% of the following 15 factors (9 or more factors)
Highly Post-Christian = meet at least 80% of the following 15 factors (12 or more factors)
1. do not believe in God
2. identify as atheist or agnostic
3. disagree that faith is important in their lives
4. have not prayed to God (in the last year)
5. have never made a commitment to Jesus
6. disagree the Bible is accurate
7. have not donated money to a church (in the last year)
8. have not attended a Christian church (in the last year)
9. agree that Jesus committed sins
10. do not feel a responsibility to “share their faith”
11. have not read the Bible (in the last week)
12. have not volunteered at church (in the last week)
13. have not attended Sunday school (in the last week)
14. have not attended religious small group (in the last week)
15. do not participate in a house church (in the last year)
Based on that criteria...here are where people ranked throughout the U.S.