[Jamestown1630]

I think Jesus was the original proponent of ‘positive thinking’ - if it wasn’t some old Greek guy...

[Songcraft]

You may be right.

(Another person in the Bible who demonstrated an extraordinary level of positive thinking, was "Job", who "had everything", lost everything, but still had enough faith to say "The Lord gave, and the Lord has taken away; Blessed be the name of the Lord."   Job 1:21.)