...I do not ask for these only, but also for those who will believe in me through their word, that they may all be one, just as you, Father, are in me, and I in you, that they also may be in us, so that the world may believe that you have sent me. The glory that you have given me I have given to them, that they may be one even as we are one...
— John 17:20-22
 

A great deal of attention has been given to Jesus' prayer in John 17 for unity and oneness among all Christians. And no doubt this is an extremely important reality for us to prayerfully understand and desire. But, it seems that many in the visible Church will do almost anything in the name of unity, even if it means compromising clear biblical teaching. We do not need to feel responsible to answer Jesus' prayer if it comes at the cost of sound doctrine. Instead, our responsibility is to follow the instruction found in God's Word regarding Biblical Community and the purity of Christ's Church. There can not be genuine Christian unity where there is not, first of all, doctrinal unity. If we do not share a Biblical standard for primary aspects of belief and practice, we aren't unified, regardless of what other cause, experience, or characteristic we share. 

Believing doctrine matters will mean doing things modeled for us in Scripture in order to defend the truth, things that will appear divisive. These are necessary to protect the true unity and purity of the true Church. Ironically, this kind of conviction has the tendency to come off as "unloving" when in reality it demonstrates a passionate love for God which, when genuine, is coupled with a sincere love for our neighbor.