How can Islam be the peacemaker of the world when Muslims fight one another?

We as muslims are to have a strong sense of unity, Quran commands this. But there are those who allow silly things to get in the way, and allow small little differences and bickerings to destroy this unity. Speaking for all muslims, atend of the day, we are all muslims, and we need to exercise peace and understanding. Quran 3:103 is a great verse the to look at pertaining to this. Many lose sight of this, unfortunately.