To be a Mere Christian is to believe that heresy is not of fundamental importance - so long as someone is a real Christian.
This is just as well, because - if we are brutally honest - each of us regards almost everybody else, even in our own denominations, as a significant heretic.
Therefore, in order to do anything; we need to work with heretics.
All we need to do as a Mere Christian is extend the charity we accord to the heretics within our own denomination to embrace heretics more widely.
What is the worst you can say of a Christian heretic?...
Can you be a Christian heretic and yet saved? Yes.
Can you be a Christian heretic and yet spiritually advanced. Yes.
Heresy is therefore, at most, a matter of mere matter of pros and cons, of statistical probability, of potential implications or consequences...
Therefore not fundamental.
We can ask - are Christian heretics fundamentally wrong, or fundamentally right?
As Christians we should say that any other real Christian is fundamentally right - that is they are right about the mst fundamental things - whatever their heresy.
That 'fundamentally right' may be very minimal - may be just enough for salvation - but that is precisely what is meant by fundamentally right.
So, every real Christian is almost certainly surrounded by Christian heretics (from his perspective, that is) - and this situation is not going to change.
Christianity requires strong, exclusive denominations and not a mush of compromise, yet there is no realistic chance of all Christians converging into a single denomination... so what is to be done?
It is a question of attitudes - Negative? Or Positive?
In a world of mutual-heretics among real Christians, should we regard each other with suspicion and mistrust, or with whatever love and brotherliness we can muster?
Surely the latter - certainly the latter.