The book to read on the current condition of religious faith in America is American Religion: Contemporary Trends, by Duke University's Mark Chaves.
For a review see here.
Chaves writes (from the book, Ch. 1) - "By world standards, America remains remarkably religious." And, Chaves says little has changed, re. religious beliefs and practices in America, from 1980 to the present. After reading chapter 1 I think the heading of the cited review ("American's religious faith waning") has an overly pessimistic spin to it. Chaves writes: "It should make us sceptical when we hear that American religion is changing dramatically or suddenly." American religiosity is neither experiencing a "dramatic resurgence" nor has it "declined dramatically." (Chapter 1)
America is becoming more religiously diverse. There are a growing number of people who are religious but claim no religious affiliation.
A growing number of young people call themselves "spiritual" but not "religious."