I 'm not studied on the "Jesus seminar" but I do know many of the main stream teachings are not based in the word.
As far as what is scripture or to be believed there are 1,000 of altered manuscripts, most just minor differences but some have whole pverses added or removed. I believe it is a point of spirit led study if truth is to be found. With that said it is a more intermediate study and not all people are there yet. As far as taking some and leaving some I think that confirming at least validity is in order before things are fully accepted, if things can be proven true than that is enough to start on and as one gains knowledge they will naturally learn more and more, making sense of the fine details that were misunderstood in the past.
With that said it is Yahshua/Jesus words above all
John/Yahanan 12:48, “He who rejects Me, and does not follow My words has One Who judges him. The word that I have spoken, the same will be used to judge him in the last day.”
John 14:23-24, “יהושע answered him, “If anyone loves Me, he shall guard My Word. And My Father shall love him, and We shall come to him and make Our home with him. He who does not love Me does not guard My Words. And the Word which you hear is not Mine but of the Father Who sent Me.”