Because of dissatisfaction with the disunity in the church, other Christians have downplayed the importance of doctrine altogether. What we have is a false "either-or" situation; some Christians believe we must separate in order to preserve doctrine, while others emphasize unity to the point of ignoring doctrinal importance.
We must reject both of these extremes. Doctrine is important. So is unity. In fact, the unity of the church is an important doctrine. All we have to do is read passages such as John 17 and I Corinthians 1 to see this.
As followers of Jesus Christ, we must embrace robust, biblical doctrine. We must also admit that there are certain beliefs that characterize all Christians. These are what some refer to as "primary doctrines." Interestingly, Christians rarely divide over these. Rather, these separate us from unbelievers. These include the virgin birth, the divinity of Christ, the bodily resurrection of Christ, salvation by grace through faith, etc. They can be best summed up in the statement, "Jesus is Lord!"
The doctrines that divide Christians are frequent.y referred to as "secondary doctrines." I've heard many Christians justify division based on these. In fact, if you read through doctrinal statements, these are the ones that define either churches or denominations. These include baptism, the Lord's Supper, spiritual gifts, church polity, predestination/free will, etc.
Here's a simple question: why can't we Christians know what we believe, know why we believe it, disagree with other Christians on some of those issues, and still remain united? I cannot understand why disagreement has to almost automatically lead to division for so many. Let's take an example: Baptists and Presbyterians. They both love the Lord and cherish the gospel message. However, they differ on baptism. What you believe determines which "camp" you are a part of, and you cannot be a part of both.
There is no good reason for this situation. We should be able to disagree and remain united. All the reasons I've heard in defense of disunity in the church are pragmatic ones. I've never heard a sound biblical defense of separation or division.
In order to remain united but disagree on certain issues, we must display a certain amount of humility. We must also act like adults. Frankly, if we demand that others agree with us and divide if they don't, then we are acting a lot like selfish little kids. This is hardly what Christ wants from his church. Also, as we are having doctrinal conversations, let's remember that we are talking with our brothers and sisters; we're not writing systematic theologies.
Let's know what we believe and why we believe it. Let's also strive for unity in the church. The two can and should co-exist. We don't sacrifice doctrine when we remain united with those who disagree with us. Instead, we are showing solid doctrine - that of unity.