Someone challenged me recently (from outside Bethlehem) to show why all decisions in the leading of a church (whether at a board level or in the congregation) should not be by complete unanimity. The form of the question was, “Where is there an instance in the Bible in which disagreement didn't include sin by one of the parties or where it didn't lead to a parting of ways? Where is an example of disagreeing on a particular issue but maintaining fellowship and working together?” We love unity and even unanimity on the Council of Elders at Bethlehem , and we want as much agreement as possible in the church when the whole church votes. But we do not demand unanimity, in order to move ahead. Here is what I wrote to explain why.
First of all, I sense a perfectionistic mindset behind the question. This mindset has a hard time living with ambiguities and imperfections and uncertainties. It tends to demand Biblical warrant for things that may not be there. I think it is fundamentally flawed to approach Scripture with the notion that the absence of teaching on necessity of unanimity can be replaced by the uniform presence of unanimity (even if it were there, which I doubt). This would be the same mindset that asks, “Is there a single place in the New Testament where there was a church building?” Conclusion: Don't build church buildings; worship in homes. This mindset tends toward sectarian isolation with a growing perfectionism that makes visionary outreach and missions almost impossible because methods are always being second guessed as insufficiently “biblical.”
But now to your question. I would go first to Romans 14. Here we have manifest disagreements. Paul's goal here was not to create unanimous thinking (as wonderful as that would be, and as much as we should pray toward it), but to help them see their way through to unity without unanimity on the issue at hand. For example, verse 5: “One person esteems one day as better than another, while another esteems all days alike. Each one should be fully convinced in his own mind.”
Then I would go to Philippians 3. Here Paul would like for them to come to one mind (as he often pleads), but he does not envision an inability to continue working together until that unanimity happens. He says, “I press on toward the goal for the prize of the upward call of God in Christ Jesus. Let those of us who are mature think this way, and if in anything you think otherwise, God will reveal that also to you. Only let us hold true to what we have attained” ( 3:14 -16). This strikes me as amazingly realistic. There are some people who are not yet persuaded. If they took a vote now, there would be differences. But Paul does not talk in either-or terms for the fellowship. He sees process and movement. There is no reason to think the whole church is paralyzed till the minority arrives at agreement. That can even happen after a vote that they disagreed on.
Thirdly, I would go to those texts that portray leaders admonishing the immature. For example, 1 Thessalonians 5:14: “Be at peace among yourselves. And we urge you, brothers, admonish the idle, encourage the fainthearted, help the weak, be patient with them all.” This seems to me to imply that there will always be a range of maturity and wisdom in the church, and that there will always be people less able to see the wise path which others see. It would be very unwise to assume that there must be a time in the life of a church when these sins and flaws disappear long enough to take a vote on some issue with no flawed thinking or feeling or acting coming into play. There is a theology of grace and sovereignty that holds sway here. God rules over endless imperfect decisions. That is the only kind there are.
Bottom line: it is a tragedy when a body of spiritual leaders, or a body of believers in general, give the least mature people the veto power over wise counsel. There is simply nothing in the Bible that says a weak and unspiritual person in the church should be able to paralyze the advance of God's people. There will always be such people. The mindset that says God only leads his people by creating a community where there is no such weakness and carnality and finiteness is, in my judgment, an unbiblical and harmful mindset.