Creflo Dollar is a televangelist and a central figure in the Name it and Claim it movement. Taffi is his wife. Creflo Dollar’s real name is, believe it or not, “Dollar”, and he teaches you... that Jesus wants you (him) to be rich.
He also claims that the Bible promises some kind of "Believer's Rights", which would give his followers his powers, such as making the bread last really long and raising the dead. Controlled experiments have at present failed to corroborate the latter hypothesis, but such things do not really concern Creflo’s ilk or followers.
Creflo and Taffi lead an extremely extravagant lifestyle (private jets, Rolls-Royces and so on). His church’s financial records are currently under investigation (here and here).
Diagnosis: Might be a complete fraud, but I have no concrete evidence that these loons don't believe what they preach. Although the popularity of the prosperity gospel televangelists seems to be in decline, these people have shitloads of money on their hands, and would have been dangerous in virtue of that alone.