Andrew Sandlin discusses marriages between Romanists and Protestants. He concludes,
I conducted an intra-faith, inter-sector wedding. In short, I conducted a Christian wedding. As a catholic Protestant, I perceive Rome as occupying a different sector of Christendom than Protestantism. It is not a different Faith (as, for example, Islam or Judaism are), but a different sector of the Faith. We Protestants join with Rome in affirming the great truths of the early ecumenical creeds and thereby the structure of orthodox Christianity. In this sense, both Rome and Protestantism constitute orthodox Christianity.
In this new found understanding of the ‘one, holy, and apostolic church’ Rev. Sandlin is not alone.
He goes on to admit that this position is contrary to the Westminster Confession of Faith, Protestant creeds in general, and both Romanist and Protestant position through all history. Of course, Rev. Sandlin believes these statements by both Protestants and Romanists to be wrong. For Rev. Sandlin, both Rome and Geneva affirm the structure of Christianity, ie. the early creeds of Nicaea, Apostle’s, and Chalcedon. The other differences between the two parties do not place them outside the realm of Christianity, and therefore, do not place them outside the realm of inter-marrying.
Allow me to defend the historic positions of both Rome and Geneva for a moment. While I do believe that Rome violates those early ecumenical creeds in practice, and thus, their profession of them is worthless, I do not believe that is the only reason Romanists and Protestants are an inter-faith wedding. Traditionally it takes more than just a believing affirmation of who Jesus is and who God is for a person to be considered orthodox or even a Christian at all. Protestants have traditional stated that if you do not believe you are saved by faith alone, then you are not a Christian. Rome has said, since Trent at least, if you do not believe in salvation by faith and works then you are not a Christian. Thus, the difference between Rev. Sandlin and both historic Protestants and Romanists is whether or not how salvation is obtained and applied part of the structure of Christianity.
The Bible seems to concentrate an awful long time on the importance of justification by faith alone. Romans 3:21-25, 4:4-5, Galatians 2:16, Philippians 3:9, and Ephesians 2:8-10 are just a few of the examples that seem to show the importance of Justification by faith alone, a doctrine which the Roman church curses. Yet, perhaps none show the difference as clearly and straight forward as Galatians 5:4. "Christ is become of no effect unto you, whosoever of you are justified by the law; ye are fallen from grace." Here the application of salvation, whether it be by law/works or faith, is linked to Christ. Those who get it wrong, do not have Christ at all. Then a marriage between one who has Christ, and one who does not have Christ is by definition an inter-faith marriage. I have to respectfully dissent from Rev. Sandlin concerning the status of Roman Catholics with regards to the Christian faith.