Historically speaking, divergent viewpoints have existed within the church since the days of the apostles. Christians have always had to live in community with other believers who do not agree with them on every single point, and they have had to do so in a way that keeps “the unity of the Spirit in the bond of peace” (Eph. 4:3). As an example of this, Paul in Romans 14 clearly intends to bring civility to Christians who are arguing over matters of diet and calendar.
No matter the particular issue, all disagreements occur only because one or more parties in the disagreement are at least partially in error. Both you and I can be wrong when we differ over something, but we cannot both be totally right. Not every error is a legitimate cause for division, and differences must be tolerated whenever they do not undermine Christian faith. Paul in Romans 14 makes this point, telling certain Christians not to judge other Christians who abstain from meat (mostly Jews still concerned with purity laws) even though no food is unclean in itself (v. 14). As long as the consciences of “the weak” did not bind the consciences of “the strong,” their view of food was tolerable.
Other errors deny those very beliefs that set Christians apart from all other people, that is, they deny those truths without which the Christian faith is impossible. Denials of the Trinity, the virgin birth, and other such matters are errors that we refer to as heresies. To preserve the purity of its testimony to the one, true God, the church has historically stood against heresy, calling councils and writing creeds to define the boundaries of orthodoxy.
Traditionally, heretics have been unwilling to admit that they do not affirm Christianity as it has been handed down throughout the ages. This problem was compounded beginning in the nineteenth century when heretics were increasingly able to stay in their churches without being disciplined for their aberrant views. Many unbelievers today are leaders in some Protestant denominations, which have suffered a mass exodus of members. The complicity of many church bodies in looking the other way when soul-damning lies are taught has forced many to flee these churches lest they be devoured by the wolves.
Paul in Romans 14 urged the toleration of those who in error felt it was wrong to eat what they thought was unclean. If this is so, should we not also tolerate those who disagree with us over issues such as the method of baptism or the millennial reign of Christ, especially when it is impossible to determine with absolute certainty which views are less faithful to Scripture than others? Are nonessential truths something over which you break fellowship?