At the time of Jesus unity prayer in John 17, not one of his disciples had a NT bound between two pieces of leather…it would be years later when Peter, Paul and John, Mark, etc would write their epistles and gospel stories. There was no NT. Jesus wasn’t praying that all believers would unify around a position but it was a prayer and call to unify around a Person.
The Gospel is clearly delineated for us in 1 Cor 15:1-4. When Paul said, “I am astonished that you are so quickly deserting the one who called you by the grace of Christ and are turning to a different gospel-- “ Paul was directing his thoughts at the Jewish legalist who were aggressively teaching and binding the old rituals and laws of a by gone era. This was a different gospel; it was a Jesus PLUS religion (Jesus + circumcision = salvation). Paul condemns them for such! (Gal 1:6)
Our denominational party lines (fences) have spawned more denominations than they have united. There’s an interesting passage in 1 Cor 1:10-12 where Paul encourages us “to speak the same thing” as opposed to shouting our different party slogans from across the fence. The phrase “speak the same thing” is a political term describing “unity of allegiance.” Our allegiance is not to a thought or a doctrine. These are the materials that build fences. Our allegiance should be to the Person of Jesus Christ. He’s the rally pole. He’s the One unity is built upon. It’s only right that Xians “speak the same” slogans of allegiance to Jesus alone. Jesus was crucified for all believers. He’s not divided. He is the common bond and He alone deserves our undivided allegiance. I thank God I am not saved by my logic or my hermeneutic, I am saved by Jesus’ perfect living and dying.
Have you ever noticed that when someone attempts to dismantle any section of the fence, he is either vilified or venerated?