Late to the talk, I am ;)
I cannot disagree that religion (many of them) have been and are divisive. Someone mentioned that religion or faith divides people into two categories: friends or enemies of God. (Even for me, this is true to a sense... though I consider a person friend or enemy to God based on what they do, rather than what they claim to believe: murder, lie, falsely accuse... not e x actly friends of God; but love one another, follow the golden rule, etc... friends of God.)
However, I see divisiveness from non-believers as well as people of faith and/or religion... as in the category of non-believers (reasonable, logical, critical thinkers); and believers (superstitious, unreasonable, unable to think critically, fearful, etc) This is a divisive attitude as well, arrogant, and also unproven. Now, there are plenty of arrogant believers, so I am not saying its okay for one and not the other. I just wish some atheists would recognize in themselves, the very thing that they are pointing out in some others.
As for co-e x istance, we have to accept that we are not going to co-exist by thinking and believing the same things. We do not have a good track record for this...in fact, humanity probably has a 100% track record at failing to think and believe the same, lol. Personally, I think we've got to stop thinking that 'we' are right, and everyone else is wrong. Whenever anyone thinks that they belong to the one group that has it right, and everyone else has it wrong, then there is divisiveness. Even if that 'group' consists of atheists.
I might not agree with the atheist on the subject of a creator, nor an atheist with me... but as a person of faith, I am not going to attack your morality simply on the basis of your non-belief. Please do not attack my ability to reason, simply on the basis of my faith.