Read Part 1.
The insistence that all things are essential (for the purpose of God’s glory) should not be mistaken for an insistence that the believer is responsible for the agreement or disagreement of others. When Paul mandates in 1 Corinthians 1:10 that believers should agree (or literally, speak the same thing) and that there be no divisions (schisms) among them, he is not suggesting that believers should try to control the thinking of others, but that believers should conform their thinking to the wisdom of God (1 Cor 2:5). In so doing, believers will become more likeminded and will better reflect the unity that is already theirs in Christ (Eph 4:1-3).
Where there is disagreement among believers, it seems there is one basic cause: fleshliness (1 Cor 1:11, 3:1-4). In James 4:1, James echoes Paul’s observation: “What is the source of quarrels and conflicts among you? Is not the source your pleasures that wage war in your members?” There it is in a nutshell. Where we have conflict, it is because I, or you, or both of us are walking in the flesh rather than allowing the Holy Spirit to bear fruit in us (see Gal 5:16-26).
But where there are disagreements among believers due to fleshliness, the prescriptions are worth noting. The “fleshly” believer is called to conform his thinking to God’s wisdom (1 Cor 2:11-13, 16) and to bear his own burden (not causing burden to others, e.g., Gal 6:5), but it is not the “spiritual” believer’s responsibility to enforce that. Rather, the “spiritual” believer is to bear patiently with the burdens of the weak, and to maintain humility (Gal 6:1-3). Both parties are cautioned not to go beyond what is written (1 Cor 4:6). In matters beyond what is written believers have freedom (even freedom to differ in opinions). So while all things are essential to the glory of God, there are areas in which He has not revealed details, and we do well to avoid dogmatism in these areas.
We need to allow each other room to grow, patiently bearing with one another as we maneuver the Christian life together. It is quite a shame that so many discussions turn to sharp disagreement and unkindness, when we have biblical models such as 1 Corinthians and Galatians to help us avoid such foolishness. Notice, for example, how gracious Priscilla and Aquilla were when Apollos had some doctrinal deficiencies. They (1) took him aside (they did not publicly humiliate him or aggressively oppose him), and (2) they explained to him the way of God more accurately (Acts 18:24-26). Apollos became a mighty servant of the Lord. I wonder what would have happened to his ministry if Priscilla and Aquilla had demonstrated less grace.
Still, there are specific instances when we see that believers are to be publicly chastised for their error. When Peter was publicly participating in the (perhaps unintentional) promotion of what turned out to be a different gospel, Paul publicly rebuked him (Gal 2:14-22). Paul also publicly reprimanded the Galatians for following after a false gospel (Gal 1:6-9, 3:1). It seems that when what is written (Scripture) is publicly distorted by believers (unbelievers are another story altogether, as we will soon discuss), there needs to be a public response. By the way—Peter corrected his ways (e.g., 1 Pet 1:14-19) and later commended Paul (2 Pet 3:15-16), so apparently things were handled maturely between them. Chastisement doesn’t have to result in enmity—and shouldn’t. As Peter put it,
To sum up, all of you be harmonious, sympathetic, brotherly, kindhearted, and humble in spirit; not returning evil for evil or insult for insult, but giving a blessing instead; for you were called for the very purpose that you might inherit a blessing. (1 Pet 3:8-9)
He also reminds that ours is not a responsibility to control the minds of others, but to be on guard against being carried away by error (2 Pet 3:17) and to grow in the grace and knowledge of our Lord and Savior (3:18).
The Bible is fairly straightforward regarding believers and agreement. We should agree on matters written in Scripture, and we have freedom even to disagree on matters beyond what is written. Where there isn’t agreement on written matters, it is due to fleshliness somewhere along the way, and there are prescriptions for dealing graciously and patiently (though firmly at times) with such disagreements.
Agreement and disagreement between believers and unbelievers, though, is a different matter. Paul’s mandate for agreement was expressly for believers. There is no mandate for believers to agree with unbelievers or vise versa. On the contrary, Paul explains that there is a core spiritual difference between how believers and unbelievers think (1 Cor 2:14-16). Consequently, Paul never mandates that believers bring unbelievers into agreement (the oft-misapplied mandate of 2 Corinthians 10:5 pertains to thoughts of believers in the process of spiritual warfare and growth). But Paul does, however, require that believers do good to unbelievers (Gal 6:10), and reminds us inasmuch as is possible to be at peace with all men (Rom 12:18). Peter demands that believers honor all people (1 Pet 2:17). Both men modeled respect and kindness to unbelievers, just as their Savior did.
We live in a pluralistic culture, with tremendous competition in the marketplace of ideas. For believers interacting with believers, we need to be careful not to be carried away by the winds of error. We need to stand firm in the truth, and we should always speak the truth in love. One without the other does not serve the purpose for which each was intended. For believers interacting with unbelievers, we need to remember that their loyalties are not to our Master, and He puts no ethical burden on them but to believe in Him because everyone needs Him (John 3:16, 20:30-31). Once in Him, we begin to learn about Him and how He would have us to live. Through His word we begin to understand that He expects us to grow and to reflect His character. We need to be patient and loving with each other as we all find ourselves in different stages of that process.
If we live by the Spirit, let us also walk by the Spirit. Let us not become boastful, challenging one another, envying one another.” (Gal 5:25-26)