Paul tells us the there must be disagreement 'to show which of (us) have God's approval' (1 Cor 11:19). We have reviewed some of the reasons for disagreement already.
Not all Christians accept the authority of the Bible.
Not all who believe in its authority have read it sufficiently to know what it says.
Many of those who have read it, in practice, rely rather on conscience, church tradition or 'words' from the Lord to reach their views on controversial issues.
If we are honest, we are all influenced by gut-feeling, reason, consensus or non-Christian authorities. We are all on a journey.
Even among those who believe passionately in the authority of Scripture and know it well there are differences over how it is to be interpreted; or (as we shall see shortly) differences over whether the end ever justifies the means, or whether it is justifiable to choose 'the lesser of two evils'.
It's essential that we approach such disagreements with an open mind willing perhaps to be shown that our deeply held convictions about the will of God are not correct. How are we to handle such situations?
First, we need to recognise that on some issues the Bible is silent. There are secret and revealed things (Dt 29:29), and while being anxious to ensure that we are obedient to the truth that is revealed, we must be careful not to let the secret encroach on the revealed. 'Don't go beyond what is written', Paul warns us (1 Cor 4:6).
Second, there are issues of secondary importance, where there is liberty to hold varying opinions. While we are not saying that mutually exclusive opinions can be equally correct, it is often more important to tolerate differences where they do not threaten major doctrines, than to risk unity by trying to persuade others around to our own point of view (Rom 14; 1 Cor 8-10; Col 2:16). Paul gives the examples of differences over holy days and vegetarian diets. While his own views are clear, he clearly doesn't think the issues worth getting steamed up about.
Third, there are issues which threaten the Gospel itself. Clearly this includes major doctrines like the atonement and the resurrection; but individual or corporate sin which threatens the witness of the church also needs to be dealt with. The circumcision issue is one such example; the nature of saving faith was under question and it resulted (quite rightly) in a major church council.
There are clear procedures in the Bible for dealing with individual sin (Mt 18:15-17; Lk 17:3-4; Jas 5:19-20; 1 Tim 5:19- 20) and it is clear from these that it's best to deal with such problems as discretely as possible, unless they involve elders, unrepentant sinners or a large section of the church.
We must be careful to hold truth and unity at tension, and not sacrifice one for the other.We perhaps need most of all to be sure that we do not fall ourselves, in trying to restore others to godly belief and actions (Gal 6:1).