I came across the quote of Tertullian's a few days ago. Thought it relevant.
In order that we may be judged to have the truth - we who walk in the rule which the Churches have handed down from the Apostles, the Apostles from Christ, and Christ from God - admit that the reasonableness of our position is clear, defining as it does that heretics ought not to be allowed to challenge [us by] an appeal to the Scriptures, since we, without using Scripture, prove that they have nothing to do with the Scriptures. If they are heretics, they cannot be Christians, because it is not from Christ that they have gotten what they pursue of their own choosing, and from which they incur the name heretic.
Not being Christians, they have acquired no right to Christian literature; and it might be justly said to them, "Who are you? When and from where did you come? Since you are not of mine, what are you doing with what is mine? Indeed, Marcion, by what right do you chop in my forest? By whose permission, Valentine, do you divert my streams? By what authority, Apelles, do you move my boundary markers? And the rest of you, why do you sow and graze here at your own pleasure? This is my property, which I have long possessed, which I possessed before you came, and for which I have a sure title from the very authors whose property it was. I am the heir of the Apostles. As they carefully prepared their will, as they committed it to a trust, and as they sealed it with an oath, so do I hold the inheritance. You, certainly, they always held as disinherited, and rejected you as strangers and enemies."
I'm interested in a Protestant's take on this. I know it's strong language, but the thought process is pretty clear and unmistakable. God gave to Christ, Christ gave to Apostles, Apostles gave to their successors. If you are not of this connected tradition, and come to believe things that have not been handed down to us, you are not a Christian. And since you are not a Christian, you have no right taking what's ours and using it as you see fit.
I know Protestants would immediately say that they are Christians because they have placed their faith in Christ, but Tertullian was talking about people who had done so too. He was talking about people had faith in Christ for salvation, who took the Scriptures, interpreted them on their own, came to their own conclusions, and believed what they thought to be the truth. And he branded them heretics.
He, of course, is not the hallmark of Christianity, but I thought the quote was interesting and would love to hear others' thoughts.