Heresy of the Week

Gnosticism - actually experiencing quite a revival nowadays.

"Matter is evil!" was the cry of the Gnostics. This idea was borrowed from certain Greek philosophers. It stood against Catholic teaching, not only because it contradicts Genesis 1:31 ("And God saw everything that he had made, and behold, it was very good") and other scriptures, but because it denies the Incarnation. If matter is evil, then Jesus Christ could not be true God and true man, for Christ is in no way evil. Thus many Gnostics denied the Incarnation, claiming that Christ only appeared to be a man, but that his humanity was an illusion. Some Gnostics, recognizing that the Old Testament taught that God created matter, claimed that the God of the Jews was an evil deity who was distinct from the New Testament God of Jesus Christ. They also proposed belief in many divine beings, known as "aeons," who mediated between man and the ultimate, unreachable God. The lowest of these aeons, the one who had contact with men, was supposed to be Jesus Christ.

from Catholic Answers