Dr. Norman Vincent Peale was a motivational speaker whose philosophy of positive thinking was rooted in his Christian faith. He passed away on Christmas Eve of 1993.
Many years ago I read his book "The Power of Positive Thinking" because it was a bestseller. It had a strong impact on my life. At the time I was selling vacuum cleaners via cold calls in the 1970s and times were pretty tough. I thought it was going to be a preachy kind of thing but instead it had a different kind of impact on my life.
I do go to church, but mostly for socialization, so I wouldn't say I'm a Bible thumper. Dr. Norman Vincent Peale was kind of the same way, I think, although he drew a lot of inspiration from the scriptures and probably didn't curse out cab drivers as much as I do. However he also draws a lot of inspiration from all kinds of thinkers and doers from past and present times.
He wrote and published almost fifty books in his life, was a minister at the Marble Collegiate Church in New York City and published a magazine called "Guideposts" with his wife Ruth Peale beginning in 1945 which continues to this day, although I believe he is probably less involved with it since his passing. He gave motivational speeches to large groups of people every year and former President Ronald Reagan awarded him the Presidential Medal of Freedom at a specific point in the 1980s.
His primary message, which I remember reading in the introduction to one of his books, was to have faith in oneself as well as in God, but I am probably quoting him incorrectly as I cannot find that quote presently. However, I do believe that is a correct paraphrase of his message. Even if you are not a "Godly" person I believe you can find something in his message.