Will Christians ever "overcome this historical burden"?? We see
more and more new denominations now, more small independent
churches, and there will be more and more in the future.
Isn't there only one God? one Salvation? are Christians not given
only the commandments to love God and to love thy neigbors? din
Jesus give only one commission, to preach the gospel? are
Christians not supposed to worship God in one and only way, in
spirit and in truth? then why so many different
denominations??
Is it good to have so many denomiations, may be yes, for the Gospel
is then preached to diff ppl in diff ways in diff places, BUT, if
there is a need for all Christians to be united, will this ever
happen?? if the anwer is NO, then different denominations is
nothing but a division of the body of Christ. 
The answer to the question is clear, many Christians put "ME" first
before God. My way of worship is more acceptable to God, my way of
running the church will bring in more believers, my method of
preaching will convert more unbelievers, my church lift up my
spirit everytime I worship, .......
I agree we should not lose focus, but don't forget the history and
the root of the problem. This is for the Christians, espcially
those church leaders to ponder on, and this has nothing to do with
non believers.