God be with you.
I like to share my opinions regarding Christian unity. I know Jesus Christ spoke about the unity for all Christians. I know the Holy See have been working hard to discuss issues of unity with the Eastern Orthodox Church, which is likely to happen in the future. I believe the unity with CC and Eastern Orthodox is possible because both have Apostolic Succession and history dates back to the infant Church.
There have been differences ideas of beliefs between East and West. In the Catholic Church, there are also Eastern Catholics or Oriental Churches. I think the link between the East might be the moving force to unit East and West. Conclusion: Eastern Orthodox Church and Catholic Church unity is possible.
In regards to Protestants Churches or Non-Catholic Christians / Evangelicals / Born-Again Christians: I do not think unity with the Catholic Church and Eastern Orthodox Church is possible. Protestant doctrines of Faith Alone and Sola Scriptura is the barrier that distance the Apostolic Churches (Catholic Church and Eastern Orthodox Church). They also have the doctrine of Once Save Always Saved (though not all Protestants believe in this), and the Rapture. These Protestant doctrines are so foreign to the Apostolic Churches, I doubt that unity with Protestants is impossible. A Protestant Christians will either have to convert to Eastern Orthodox or Catholic Church, or cease to be Protestant.