Well, there are many problems with it actually, but when you hear people like Joel Osteen stating that when you are in relationship with God, you can expect the favour of God, that you can actually expect good things to happen to you, it is a very dangerous (not to mention heretical and unbiblical) statement to make. If Osteen is right then Jesus himself must have been pretty out of favour with the Almighty! The One who is described in Isaiah as a man of sorrows, familiar with suffering, is the Jesus of the Gospels, who was born in a trough, was the friend of sinners and of the scum of the earth, the people who no one else wanted to be around, and was constantly in tension with the religious establishment and the powers of His day, and was of course eventually crucified for his efforts. According to Osteen’s theology then, Jesus was a failure (and not just in the worldly sense, but in a spiritual sense as well). When people in favour of this doctrine quote the Bible, notice that they almost overwhelmingly quote the Old Testament, and then in bits and pieces. My pastor once said that a verse taken out of context is a pretext; in other words, you can take a few single verses and put them together to say exactly what you want them to say. Now, I am convinced that the Old Testament is just as much the Word of God as the New Testament. But when these people hardly ever quote the New Testament in defence of their prosperity doctrine, particularly the Gospels which deal explicitly with the sayings and life of Jesus, there is a problem. Christians who don’t talk about Jesus – how’s that for an irony?