I noticed you glossed past this:

First, matter or the material is not evil. It is true that the Bible focuses on the sins of the flesh and not be concerned with the problems of this world. However, God did give us a body and it is a temple. Often an over-emphasis on asceticism can lead to gnostic thinking.

Second, there is one God and he is all-powerful. He is not in conflict with evil or fighting evil. He allows evil to exist.

Third, salvation is not determined by knowledge or a certain level of enlightenment. The doctrine of faith and works contradicts Gnosticism. If knowledge were the key to salvation then there would be no need to do works of charity.

Fourth, We already have Jesus. Anyone claiming to have the knowledge of salvation that is in conflict with Jesus as a gnostic would be is a false profit. A good tree does not bear bad fruit. Judge these gurus by their fruit.