The gospel writers report Jesus as praying a lot. He would get up early, find a 'lonely' place and be in communion with his Father. (Mark 1:35) Included in his times of prayer were requests of all sorts. Among other things, he prayed all night before selecting the twelve apostles, presumably asking the Father's counsel about it.
My conviction is that his most fervent prayer was that his followers would be one, that they would be united heart and soul. "I pray that they all may be one as you, Father, are in me, and I in you. I pray that they may be one in us so that the world may believe that you have sent me... that their unity may be complete. It is by this that the world will know you have sent me." (John 17:21-23) It is important, therefore, that we be one because God himself is one, and also because our unity will be the effective cause of people's coming to faith.
"The Lord calls people together to share their lives with one another in him and so that he can use them to do his work. That's where the vision for any community comes from, from the overall plan of God to accomplish his purposes through bodies of disciples. It is their unity that God will use to make their work effective. It is their divisions that will bring vision down."
Unity is God's doing. The Father, being perfectly one with the Son and the Holy Spirit, operates best through people who are one with him and one with one another. Because we tend so easily to divide one from another, the path to unity the Lord places us on will require a lot of purification, a lot of sandpapering. Strong and lasting unity among a body of disciples, among the members of a community, is hard to come by. Are some saying impossible? Not at all. Rare perhaps, but not impossible. Nothing is impossible with God. (Mark 14:36) If God wants it, he can make it possible. It is for me to desire it with all my heart and to work for it with everything I've got.