I understand that some people have not studied both sides of the OSAS issue, but I am not one of them. I was raised in a church with a Calvinistic background and accepted OSAS without question until I really go into Bible study when I was 40 and came under conviction to leave gay life.
I started by throwing out every thing I had been taught and went from there. I know I accepted some errors by doing this but I had to do this my way. Then I went back and compared both sides of a long list of "doctrines" and "beliefs" that are commonly held among Christians.
You can stick to Hebrews but to understand Hebrews 6:4-6 you have to take the whole book into consideration, and to fully understand what Paul is teaching in Hebrews you have to understand all that Paul believed and taught by the inspiration of the Holy Spirit. False doctrines are built by taking one or two verses out of the whole Bible; tongues, OSAS, the timing of the "rapture" and a multitude of other belief systems fall into this category.
If you take the time to read the other threads we had going on OSAS you can easily discern how violent these discussions can become. Both the webmaster and I were called everything from the personification of the antichrist to “spawn from hell” only because we do not accept OSAS as true.
I will no longer engage in any debate concerning OSAS because it is too divisive a subject. But, I will question your interpretation of some aspects of what you post, i.e. the assumption that Paul was writing to non-believers in his epistles when he in fact states he is writing to professed Christians and that the early church did not have Scripture to refer to.
I listed Wuest's outline just so we could get a general flow of the book of Hebrews sinse there seemed to be a disagreement earlier about what it was, in a general sense, teaching.
I could copy and paste an outline from Scofield, and others who take both sides of this issue that would disagree with Wuest.
Appealing to one man or one theological stance is not necessarily appealing to God's truth. Read the Catholic catechism and how they avoid God's truth, Greek grammar, and other historical facts to establish some of their doctrines.
God's word explains and interprets God's word; we don't need biased theologians telling us what to believe when we have His word and the Holy Spirit to help us discern His truth.