I do not deny the existence of this phenomenon, or say that it is impossible. Some really thought-provoking material has come through some channelers. Like you, I was impressed by some of the early "Seth" material.
But using Occam's Razor, all the teachings appeared to have originated with Jane Roberts. Perhaps she was no "genius," but she was not so poor at expression that she had to give credit for her work to another being-- an extradimensional called "Seth." In all fairness, she probably did literally believe that she was "channeling" another being-- although many later "channelers" were simply bad actors. The woman who "channeled" Ramtha was a big fad in the metaphysical community, but defecting followers reveal that she used to make fun of her contributors and those who gave her thousands of dollars! She bought an Arabian racing horse and an expensive ranch with their money.
Every once in a while, a "channeler" will say something valuable. So, we need not reject them all. In fact, the Way of Love can be interpreted as a similar path; we are supposed to empty out the ego to make room for the Holy Spirit. And then, we are supposed to "channel" God or Love.
But every other person sought to jump on the "bandwagon" of "channeling."
And this is not healthy, for either the individual student or for the community. For example, some channelers were so confused that they said that "right" and "wrong," "good and evil," did not exist! They fell into a confused relativism that provided no guidelines whatsoever. This is, as noted, where a good spiritual teacher comes in handy.
She can help us sort through the thousands of channelers and their tens of thousands of ideas to produce a pure collection of valuable truths.
The situation is like a mountain of mud that contains a few real diamonds. Sometimes, you have to go through a lot of mud to find a diamond! A teacher can do you the favor of reading and sorting through all this material, and can aid and assist you to find ideas that are truly useful and valuable.
Beings from distant planets, or equally distant dimensions (universes) do not often say things that are practical, realistic, or useful. One of the great and real strengths of the truly spiritual is that it is practical; it is something that we can apply to better our minds, or our lives, this very morning!
Channelers lie upon a sliding-scale spectrum, ranging from those which are valuable and useful to those which are almost comedic in approach.
They vary from extraterrestrials and extradimensionals to dead people from Atlantis. I have read most of the channeled material, and have heard most of the tapes. Color me unimpressed!
I simply insist upon reason. What would it take for you to believe that an ordinary person was "really" an extraterrestrial, extradimensional, or Spirit of incredible enlightenment? For us, it would require more than a simple claim. For anyone, even a fool, or mentally-disturbed person, can make the claim. The claim to be "channeling" is itself worthless, and proves absolutely nothing!
Channelers need to be tested. Challenge them to do a math or chemistry problem from a high-school textbook, and see whether they are really supermental, superspiritual superbeings from some superplanet! In this case, a little skepticism can be handy and protective!
Many channelers jumped on the bandwagon, and native Americans joined extraterrestrials and many extradimensionals in predicting the "end of the world" in 1999. Now, many are also jumping on the 2012 bandwagon.
But I have put out a challenge: Anyone who believes that the "end of the world" is coming in 2012 is challenged to sign a legal document that gives all their worldly possessions to Love Ministries on January 1, 2013. So far, we have had no takers, and expect none! They refuse to "put their money where their mouth is"!
Only time will tell, of course. But the challenge still stands unmet, and is likely to remain so.
There is still much, much more that could, and perhaps should, be said.