The primary issue with the westboro baptist church isn't one of doctrine, though I'm sure if it were laid out there would be serious doctrinal errors, but one of missing the spirit. They preach a heavily law-centric ideal but in doing so excuse the sins for which they themselves are guilty by trivializing such things. They preach no gospel at all because all they preach is condemnation for sins, and Jesus came not to condemn the world but to save it. Their extremism more exposes some of the central flaws from a Calvinistic view of God in that the sovereignty of God becomes so fetishized, and "purity" becomes such a focus, that there is no room for grace. God becomes a tyrant dictating lives to the smallest scruple, and any deviation is deserving of hellfire. Yet when we turn to the Bible that is not the God revealed in it's pages. Instead, He desires that all should come to repentance and He is longsuffering in our faults. The god revealed by groups like the westboro baptist church cannot properly said to be Love. Merely a cold, judgmental and unforgiving beast punishing all who dare stray from the path. Certainly not the Shepherd I've found in Jesus.