Positive Thinking has nothing to do with Biblical Faith
Positive thinking is unrealistic. Just thinking nice, desirable and positive things… so what? It’s easy to slip into New Age thinking that leaves God out. I, I, I… instead of God cares comprehensively for me. “Positive Thinking” (New Age) vs. optimistic belief (Bible).

How much easier do we have it as Christians. We can always be optimistic. Always. Why? Because God promises beautiful, good things and His help. And God does not lie.

2 Corinthians 3:4-6

“And such trust have we through Christ to God-ward: Not that we are sufficient of ourselves to think any thing as of ourselves; but our sufficiency is of God; Who also hath made us able ministers of the new testament; not of the letter, but of the spirit: for the letter killeth, but the spirit giveth life.” (2 Corinthians chapter 3, verses 4-6; KJV)