I don't think we'll ever reach the point where every Christian agrees on everything - at least, not until Christ returns.

Still, there are ways to disagree without breaking fellowship. When Paul stresses likemindedness, I don't think he's saying that all of us have to walk in lockstep at every point (same tastes in music, same interests in literature, same views on every social issue, same styles of clothing). Nor do doctrinal disagreements necessarily violate Paul's call to likemindedness.

Certainly in Philippians 2, the call to likemindedness comes in a context where Paul is calling the church to be united in living out Christ's mindset and having a life that matches her heavenly citizenship and that fits with the gospel she preaches.

And Christ's mindset is probably the key. Likemindedness flows from humble service to others, considering others more important than yourself. If the church would do that, it might give us a new perspective on a lot of our doctrinal difficulties and the patience to work through them together.