Misleading distinction?

If it is the case that "we are not justified by believing in justification by faith but rather by believing in Christ" (Acts 16:31; Romans 10:13) is there any meaningful way in which we can say that there are some beliefs that are essential and some that are non-essential? If as implied by the quote above, that there are some who are utterly clueless/mistaken on the issue of justification but who will still make it to glory, then isn't it better to identify those who are orthodox by another criteria: culpable verses non-culpable ignorance of the truth. In other words, if the Church were to have an Acts 15 type council to determine if someone/a church is outside the faith or not, I think a more helpful criteria to adjudicate on this, would be to examine if the person/church was excusably ignorant of doctrine "x" rather than trying to determine whether the doctrine they deny fits into the nebulous category of essential/non-essential. This prevents individuals/churches from the double standards of sitting high and mighty over others on matters they deem important whilst ignoring/trivialising other so called 2nd order issues which the Scriptures speak rarely but nevertheless clearly about e.g. that the drink served at communion should be wine and not grape juice; that having children who are unfaithful should disqualify one from being an elder; that Capital punishment is mandated and endorsed in Scripture and so on. I suppose another way of putting all this is to say that everything which Scripture teaches (explicit or implied) is binding OR as Someone once put it until heaven and earth disappear not the smallest letter, nor the least stroke of the pen will by any means vamoose