How do you know if you are being led astray?

Jesus never quoted his 'feelings' to the devil, did he? He quoted Scripture, is that right? We are commanded to test the spirits and to weigh feelings and teachings by Scripture. Both mormons and charismatics are big on basing their urance on what they feel. Since they didn't come to their conclusions through reason, reason has almost no effect on getting them out of deception. One RC lady told me that she sincerely seeks truth, so how can she be deceived by visions of Mary, saints, etc? But, she did not read her Bible much. I've heard New Agers go on about the great inner peace they have. Don't listen to anyone who says other religions and cults don't produce feelings that they claim to have. They are already filled with satan. The sleep of reason produces nightmares-Goya