Jesus' disciples were made up of all sorts of people. He chose Peter, someone who was ready to take on all of Rome, and He chose Matthew, a tax collector and someone who might be considered a traitor.
The people Christ calls into His family varies as well. How can we have unity? It is only when we are grounded in Christ and recognize that we each have something different to contribute to the overall work of the church. It's not about doing all the same things the same way with the same people.
The sermon in the link below begins the second half of Ephesians where true unity is described in practical terms.