The Lord Jesus Christ commanded us to "believe the gospel" (Mark 1:15). God saves through the gospel (Rom 1:16). Because of this, we preach the gospel to every creature (Mark 16:15). Paul served God in the gospel (Rom 1:9). If anyone preach any other gospel than the one Paul preached, he is to be accursed (Gal 1:6-9).
I'm deeply concerned about a widespread movement, much more than a trend, that claims to exalt and celebrate the gospel, when it in fact attacks the nature of the gospel. It's taken me awhile to sort this out, but now I'm convinced that this movement undermines the gospel, meanwhile promoting what it says is the gospel. I am calling it a leaking gospel. It is an imposter that might be decorated with flags and bright colored paint, but it has enough holes to sink it. What leaks out from it is what God created the gospel to do. Contained in the gospel is the power to change, to sanctify, and to separate, all around the truth.
The problem of the leaking gospel centers on an important gospel text in the New Testament---1 Corinthians 15:1-4. There Paul writes to the Corinthians:
Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures:
What is the normal use of protos, "first." Should it be understood as "first importance?" The first time we see protos in the New Testament is in Matthew 5:24, which says, "first be reconciled to thy brother." The primary usage of protos is order, not importance. Even if en protos does mean "as of first importance," which it doesn't seem to according to a common sense reading, nothing in the context would tell us that 1 Corinthians 15:3 is making the amazing statement that this is the most important doctrine in Scripture. And then if it really is saying that the gospel is the most important doctrine in the whole Bible, it doesn't say anything about the gospel being the only test of fellowship with other professing believers. This is not exegesis of 1 Corinthians 15:3. It is all reading this teaching into 1 Corinthians 15:3.
A plain reading of the text says that Paul is saying that the gospel was one of the first messages that he delivered to the Corinthians. Of course, he would preach the gospel to them first because they weren't saved. The gospel is foundational to other doctrines, because someone can't understand Scripture until he has been converted and has the Holy Spirit indwelling him. A person goes to Hell for all eternity if He rejects the gospel. There's no doubt it's important, but it is a massive jump to seal a most-important-doctrine-in-all-of-Scripture alone from 1 Corinthians 15:3.
This little two word Greek phrase has become the proof phrase for a particular belief about the gospel. From those two words, those in this leaking gospel movement say in essence that the gospel is the singular basis for Christian fellowship, that is, as long as someone has even a minimal understanding and then reception of the gospel, we are permitted to fellowship with him regardless of many other scriptural differences. With most of these, it goes even further than that. To them, those who separate over the violation of a scriptural doctrine or practice other than or in addition to the gospel somehow are diminishing or undermining the gospel.
When we are saved by grace through faith alone (Eph 2:8-9), "we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them" (Eph 2:10). Right behavior "adorn(s) the doctrine of God our Saviour in all things" (Titus 2:8-10) for God's grace "teach(es) us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world" (Titus 2:11-12). John writes in 1 John 2:29: "If ye know that he is righteous, ye know that every one that doeth righteousness is born of him." Whatever is truly about the gospel can't divide itself from all of the teachings of the Lord. The gospel changes someone to live everything that God said.
The gospel is not the only basis for fellowship. In one of the most important and few passages on unity in the New Testament, Ephesian 4:3-6, we see that unity is based upon "one faith." "The faith" encompasses all the teaching of God in Scripture. "The faith" is everything that we believe and practice as a church. It is what brings a church together---not just the gospel, but all the teaching of God's Word.
"The leaking gospel" is more concerned about the alliances of evangelicalism and fundamentalism than it is about the gospel. Someone who loves the gospel won't compromise something else in Scripture in order to "get along" with another professing believer. Those with this understanding of the gospel are more concerned about their kind of unity than they are the honor of God. God isn't honored by diminishing belief and practice to cobble together leagues, fellowships, denominations, and confederations. Those with "the leaking gospel" don't mind the erosion of true worship in order to keep an alliance together. You can see that this view of the gospel doesn't strengthen the teaching of the gospel, but empties of it of its power by cheapening the grace of God. God's grace conforms men to all that God said. That was why Jesus sent His church to teach new believers "to observe all things whatsoever I have commanded you" (Matthew 28:20).
So I say beware of those with the leaking gospel. They may talk of the gospel and bring it into most conversations. They may say that it is what their preaching and their worship is all about. That doesn't mean that they represent the gospel of God. Just because they claim to coalesce around the gospel does not conclude that they do.