John Owen argues that denying true doctrine does not mean that you are unsaved. He writes, “Men may be really saved by that grace which doctrinally they do deny; and they may be justified by the imputation of that righteousness, which, in opinion, they deny to be imputed.”
So someone may deny imputation by justification or other key doctrines and be saved. Why? He explains, “for the faith of it is included in that general assent which they give unto the truth of the gospel, and such an adherence unto Christ may ensue thereon, as that their mistake of the way whereby they are saved by him shall not defraud them of a real interest therein.”
The point is that assenting to the Gospel of Jesus that he died, rose, and ascended for and for our salvation sufficiently provides us salvation. Or in the Reformed idiom, assenting to the promise of God makes one a Christian.
Obviously, Owen desired right belief and taught vehemently the truth. But he knew that doctrinal precision did not make one a Christian; accepting Christ does. And even denying imputation if one still accepts the Gospel does not deny salvation.
In this case, their mistake “shall not defraud them of a real interest” in Christ.
Our errors, our mistakes, our wrong beliefs can never take away our justification in Christ.
We are saved by grace alone through the remission of sins and imputation alone. Not by our intellectual works, knowing the precise doctrine; nor do our sins or our doctrinal mistakes take away that salvation.
This is not to deny that knowing true theology by the Spirit grows us in joy, nor is to deny that the Spirit leads us into all truth.
But it’s to affirm justification by faith.
To declare that someone who accepts Christ alone for salvation while mistakingly denying imputation (or other like doctrines) denies this person salvation almost seems to make salvation rely on works.
This is something that Reformed believers should be careful of. For they may find themselves accepting Christ not alone but on the basis of their intellectual works. And this certainly denies someone salvation.