Interpretation of the scripture “One Lord, one faith, one baptism?”

Question

Ephesians 4:5 states there is "one Lord, one faith, one baptism." Some Christians interpret this to mean that a single denomination (with its beliefs, doctrines, and practices) constitutes the "one true faith." Other Christians interpret this to mean that a group of denominations (with their collective beliefs, doctrines, and practices, which are sometimes different or even contradictory) constitutes a collective "one true faith."

What are the respective arguments for these two interpretations of the scripture?

Answer 1

The Bible doesn't talk about denominations, nor did Jesus or any of the disciples start any denominations. Denominations came from the disagreement of men on the interpretation of the Word of God. For this reason, I do not believe this passage can refer to denominations, which didn't exist when Paul wrote it.

Paul insisted in various places on the unity of the doctrine. For example in 1 Timothy 6:3, he insisted on the supremacy of the teachings of Jesus:

If anyone teaches otherwise and does not agree to the sound instruction of our Lord Jesus Christ and to godly teaching,

In Galatians 1, he warned against false teachings:

⁶ I am astonished that you are so quickly deserting the one who called you to live in the grace of Christ and are turning to a different gospel— ⁷ which is really no gospel at all. Evidently some people are throwing you into confusion and are trying to pervert the gospel of Christ. ⁸ But even if we or an angel from heaven should preach a gospel other than the one we preached to you, let them be under God’s curse! ⁹ As we have already said, so now I say again: If anybody is preaching to you a gospel other than what you accepted, let them be under God’s curse!

In 1 Corinthians 1, he warned again about disagreements between teachers and the importance of recognizing yourself as a disciple of Christ rather than as belonging to a specific teacher (or "denomination", as we would call it today):

¹³ Is Christ divided? Was Paul crucified for you? Were you baptized in the name of Paul? ¹⁴ I thank God that I did not baptize any of you except Crispus and Gaius, ¹⁵ so no one can say that you were baptized in my name. ¹⁶ (Yes, I also baptized the household of Stephanas; beyond that, I don’t remember if I baptized anyone else.) ¹⁷ For Christ did not send me to baptize, but to preach the gospel—not with wisdom and eloquence, lest the cross of Christ be emptied of its power.

I think Ephesians 4:5 is then quite clear.

• There is one Lord, the Lord Jesus Christ;
• There is one faith, the faith transmitted by the apostles (that includes Paul);
• there is one baptism, the one transmitted by the apostles.

All other teachings are to be rejected.

Answer 2

I'll answer from the perspective of a member of one denomination within a larger church.

We are all part of one body, Christ's church. But not every part of the body has the same function.

For as in one body we have many members, and not all the members have the same function, so we, who are many, are one body in Christ, and individually we are members one of another. —Romans 12:4-5

Just as individual believers have different roles within the work of the Kingdom of God, individual congregations may be stronger in certain areas than others. But if we recognize that we are all part of the same body, we can each contribute our part.

I don't know who first said it—I've seen it attributed to many Christian leaders from the past—but this quote captures the ecumenical spirit:

In essentials, unity. In non-essentials, liberty. In all things, charity.