'Ideas of a purely symbolic resurrection were later developed by a group called Gnostics. Believeing that knowledge could be derived in a mystical way, Gnostics combined apostate Christianity with greek philosophy and Oriental mysticism. For instance, they held that all physical matter is evil, and for that reason Jesus did not come in the flesh but only seemed to have a human body.'
It is interesting to see the Watchtower launch an attack against Gnosticism in this way, but they carefully avoid the fact that the Bible itself tells us that the physical creation is in a ' fallen ' state. Afterall, there would be no need for a 'new heavens & a new earth' if all was ok with the current creation. So surely, if the Bible is true, matter is infected with imperfection and has a propensity towards evil?
It is also a very simplistic view that they present in the article - "all matter is evil" ... the guys who wrote the article are not presenting the full idea I would suggest, as certain Gnostics would have viewed matter as the grinding wheel to sharpen their spiritual sword upon, so therefore it was necessary evil. Duality is part of this existence and one could argue that God himself uses evil in order to produce good works within the heart of man.
So, like the Gnostic Christian sects, the orthodox believers also view matter as being impure based around Bible ideas.
Also, Paul it would seem, had Gnostic leanings himself, when he describes a division between flesh & spirit. The famous passage attributed to Paul describes a battle taking place within himself. Very, very, Gnostic - wouldn't you say?
From what I have read concerning Gnosticism, it seemed to have been a part of the early church and was then cut out by the church fathers who began organizing the religion. As has already been stated, to maintain control, they would have had to diminish the concept of individual spirituality; forcing allegiance to a hierarchical church.
As for Christ not coming in the flesh - who can say for sure that he did? Surely, that is a matter of faith, not of objective evidence?