THE PROBLEM WITH THE WORD OF FAITH THEOLOGY
In the case of Joel Olsteen, and those like him, they've used the our worldly needs to entice us. We all need health, desire wealth, lust for beauty, and dream of fame or popularity and these teachers caters to our desires (1 John 2:22-23). The problem is that not only it doesn't work, but they've taught that your healing, wealth, and fame is dependant on your faith and giving ($$$).
If you're not healed, you didn't have enough faith; and if your illness returns then you must have sinned some time ago. Imagine the guilt that would come as a result of. Worse, some refused medical attention because of that teaching; many died because of it. That's not what the Bible taught. When you're healed, you're healed; but if you've sinned unrepentantly a worse thing will come (John 5:14).
And with regard to giving; that's how pastors like Jimmy Swaggart, Benny Hinn, and Creflo A Dollar, in the Word of Faith movement got, filthy, rich. John Macarthur, Pastor of Grace Community Church in Los Angeles calls it a Ponzi Scheme, and it is (he preaches against the Word of Faith movement along with Justin Peters, Costi Hinn, and John Piper).
Costi Hinn, Benny Hinn's Nephew tells of them staying in 50 thousand dollar hotels in Dubai, owning multiple mansions, and flying in private jets.