Worthy men such as Alistair Begg and John MacArthur explained why they were unable to sign the Manhattan Declaration.
Shortly after, in Nineteen Questions for Signers of the Manhattan Declaration, I tossed in my widow's mite. The post demonstrated that the document (A) was necessarily theological, (B) unfortunately communicated some significantly bad theology, from the perspective of Biblically-faithful Christianity, and that (C) it was not a document that someone concerned with the clear delineation, definition, and declaration of the Gospel should want his name associated with.
Then in NEXT! #19, we skewered the dodge that refusal to sign the document had anything to do with unwillingness to "work with" anti-Christian faiths in opposition to abortion.
After that, Michael Horton also published a demurral.
Now R. C. Sproul has contributed a forceful, gracious, and yet trumpet-like blast to the discussion. In The Manhattan Declaration: Why didn’t you sign it, R.C.?, Sproul gives eloquent voice to the same basic objections that others of us also sounded. Here are just a couple of particularly choice extracts.
While I would march with the bishop of Rome and an Orthodox prelate to resist the slaughter of innocents in the womb, I could never ground that cobelligerency on the assumption that we share a common faith and a unified understanding of the gospel.
The framers of the Manhattan Declaration seem to have calculated this objection into the language of the document itself. Likewise, some signers have stated that this is not a theological document. However, to make that statement accurate requires a redefinition of “theology” and serious equivocation on the biblical meaning of “the gospel” (2 Cor. 11:4).
...how could I sign something that confuses the gospel and obscures the very definition of who is and who is not a Christian? I have made this point again and again since the days of ECT. Though the framers of the Manhattan Declaration declaim any connection to ECT, it appears to me that the Manhattan Declaration is inescapably linked to that initiative, which I have strenuously resisted. More than that, this new document practically assumes the victory of ECT in using the term “the gospel” in reference to that which Roman Catholics are said to “proclaim” (Phil. 1:27).
The Manhattan Declaration puts evangelical Christians in a tight spot. I have dear friends in the ministry who have signed this document, and my soul plummeted when I saw their names. I think my friends were misled and that they made a mistake, and I want to carefully assert that I have spoken with some of them personally about their error and have expressed my hope that they will remove their signatures from this document. Nevertheless, I remain in fellowship with them at this time and believe they are men of integrity who affirm the biblical gospel and the biblical doctrines articulated in the Protestant Reformation.
...It is only in our united proclamation of the one, true gospel of Jesus Christ that any heart, any mind, or any nation will truly change, by God’s sovereign grace and for His glory alone.