The Bible has a lot of stories that promote positivity, not because of an ability or a possession, but because of trust in God. The Apostle Paul gives one of the more compelling statements in the Epistle to the Philippians when he enumerated several positive thoughts that a Christian should think about.
Some of the things he pointed out include purity, honesty, beauty, goodness and other positive things. In a world full of negativity, the Christian should rise to the occasion and show his light, the light which comes from God.
It is interesting to point out that the Apostle Paul was in prison when he talked about positivity. This means positive thinking is not just hoping for the best, but placing your trust in a God who will never leave you nor forsake you.