"Has it ever occurred to you that one hundred pianos all tuned to the same fork are automatically tuned to each other? They are of one accord by being tuned, not to each other, but to another standard to which each one must individually bow. So one hundred worshippers meeting together, each one looking away to Christ, are in heart nearer to each other than they could possibly be were they to become "unity" conscious and turn their eyes away from God to strive for closer fellowship. Social religion is perfected when private religion is purified."
- A.W. Tozer
And here are a few other quotes on unity.
In necessary things, unity
in doubtful things, liberty
in all things, charity.
-Saint Augustine
Father, the hour has come; glorify your Son that the Son may glorify you, since you have given him authority over all flesh, to give eternal life to all whom you have given him. And this is eternal life, that they know you the only true God, and Jesus Christ whom you have sent…
…I have manifested your name to the people whom you gave me out of the world. Yours they were, and you gave them to me, and they have kept your word. Now they know that everything that you have given me is from you. For I have given them the words that you gave me, and they have received them and have come to know in truth that I came from you; and they have believed that you sent me. I am praying for them. I am not praying for the world but for those whom you have given me, for they are yours. All mine are yours, and yours are mine, and I am glorified in them. And I am no longer in the world, but they are in the world, and I am coming to you. Holy Father, keep them in your name, which you have given me, that they may be one, even as we are one…I do not ask that you take them out of the world, but that you keep them from the evil one. They are not of the world, just as I am not of the world. Sanctify them in the truth; your word is truth.
As you sent me into the world, so I have sent them into the world…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, I in them and you in me, that they may become perfectly one, so that the world may know that you sent me and loved them even as you loved me…O righteous Father, even though the world does not know you, I know you, and these know that you have sent me. I made known to them your name, and I will continue to make it known, that the love with which you have loved me may be in them, and I in them.”
- Jesus
