Mark 13:3-6 (ESV)
And as he sat on the Mount of Olives opposite the temple, Peter and James and John and Andrew asked him privately,  "Tell us, when will these things be, and what will be the sign when all these things are about to be accomplished?"  And Jesus began to say to them, "See that no one leads you astray.  Many will come in my name, saying, 'I am he!' and they will lead many astray.
See that no one leads you astray. I think the problem is, we don’t need to be led astray. We’re wont to go astray, so it doesn’t take much in the way of leading at all. People come and tell people what they want to hear, and they are gone. This happens whether the man comes preaching libertinism, or moralism, or a mixture of the two. Our old Adam wants to hear moralism, boundaries, do this don’t do that, just as much as he wants to hear a defense of hedonism. He will hear one or the other, but not the gospel. The others let him pretend to be God, master of his own destiny, but the gospel forgives sins, and recognizing we need forgiveness takes the power away from us to do anything. It deflates our ego. It puts us in our place, and reminds us that we in fact are not gods, we do not belong to ourselves. But then, when you are given the gift of faith, given the ability to live with forgiveness, Its hard to go either of the other two ways for very long. When you live in the love of Christ, and by the love of Christ, well it won’t let you be either a moralist, or a hedonist, it won’t allow you to be anything but a forgiven sinner.