Positive thinking?

A new book, "Bright-sided: How the Relentless Promotion of Positive Thinking has Undermined America," by Barbara Ehrenreich caused me to reflect on my own worldview. Has American Christianity been corrupted? I have been weighing this since I became a Christian in 1979. I was caught trying to harmonize Dale Carnegie and Norman Vincent Peale with Jesus. Maybe Joel Osteen, Robert Shuler and others have co-oped the gospel. I think Zig Ziglar is somewhere in between. I don't know the answer. I think that the answer lies somewhere in the book of James.