Jesus did not come to teach about the world and how to succeed here; he came to teach about the ways and means of heaven.  Efforts at exegesis that fail to realize that, however well-intentioned and ingenious, are fundamentally misoriented.

Still, there are occasions where what Jesus teaches about heaven finds echoes in what others teach about the world. 

One of these is His instruction concerning trust and confidence in the future.  Regard the lilies of the field!

Worldly writers do also sometimes encourage an optimistic attitude – The power of positive thinking! – and their evidence is how frequently it leads to worldly success, sometimes far exceeding reasonable expectations.

‘Deeper’ thinkers, though, are often condescending towards such writers; they knowingly point out, with unassailable evidence, how often the world clearly and even tragically disappoints optimism.  Expect the worst, and you’ll never be disappointed is their proud slogan.  They argue persuasively that optimists are, at best, successful entrepreneurs, advocating a positive attitude as a useful tool in one’s worldly dealings, along with discipline, self-control, energy, and so on.  It increases the odds of success.

But to repeat, Jesus is not talking about the world at all, except in the sense that there are elements in the world that mirror – or perhaps retain – elements of heaven.

We are encouraged by our Lord to cultivate in ourselves a positive attitude towards the future, not because it will help us get ahead in life or get the most out of life – although it very well may do both those things, and other good things besides – but because it will make the transition from here to heaven less dramatic.  It will not require losing the demonic pleasures of pessimism.