I believe one of the best Scripture passages we can examine to understand the dangers of the spiritual enterprises of New Age, Mormon, Glenn Beck and his “evangelical” participates would be Acts 16:16-18:

Now it happened, as we went to prayer, that a certain slave girl possessed with a spirit of divination met us, who brought her masters much profit by fortune-telling. This girl followed Paul and us, and cried out, saying, “These men are the servants of the Most High God, who proclaim to us the way of salvation.” And this she did for many days.
But Paul, greatly annoyed, turned and said to the spirit, “I command you in the name of Jesus Christ to come out of her.” And he came out that very hour.

Notice that the girl was possessed by demons and Paul knew this was the case. Paul did not want the endorsement of the demons even if they were speaking truth by stating “These men are the servants of the Most High God, who proclaim to us the way of salvation.” Why? Because Paul knew that Satan will proclaim truth in order to attract a crowd, to gain credibility only to then undermine the gospel. I believe this is exactly what Glenn Beck has done with his religious talk that appeals to Christians and undiscerning evangelicals. Yet, as a self-professed Mormon Glenn is mixing truth with error which is Satan’s strategy for infiltrating the church with a religious Trojan horse.