The spirit of the world whispers through a thousand different channels that if only you can be successful enough (at sport, business: ideally everything) or beautiful enough, or sexy enough, or famous enough, you will be secure, fullfilled, happy and contented. Of course this is all a lie. Achieving these things for wordly reasons will at best leave you feeling insecure and uncontented, or at worst it will leave you feeling arrogant and confident, but strangely deeply insecure at the same time - as if you know the things underlying your confidence can easily disappear leaving your 'ego' naked and insecure again.
The opposite to the spirit of the world is the spirit of God. This says - very quietly and modestly - that all those worldly things mean nothing. That your worth comes from intrinsic, spiritual things, not material external things. The spirit of God tells us that what makes us valuable is our love for others. That if we seek our worth in our measure of love for others that we will find not only self-assurance but also deep contentment and joy. And such feelings can never be taken away from us, as they are based within ourselves, within our very being, not on anything external to us. Therefore they are our true posession for eternity.