“I pray not only for them, but also for those who will believe in me through their word, so that they may all be ONE, as you, Father, are in me and I in you, that they also may be in us, that the world may believe that you sent me. And I have given them the glory you gave me, so that they may be ONE, as we are ONE, I in them and you in me, that they may be brought to perfection as ONE, that the world may know that you sent me, and that you loved them even as you loved me."
This command is being obeyed today by Christians who do not judge according to outward appearance(denomination) but according to their faith.
In many protestant circles they do no regard each other as, a methodist or a baptist or a Luther,, they regard each other as a fellow brother in Christ. The scriptures says to to good for them of the household of faith.
I think that some Catholics are begining to think like this as well. The pope has made statements that protestants are of the faith.