If the Sunni-Shia Muslims division is a political division, then how do you explain certain differences between the two, which are purely religious, such as the sacredness of Muharram (Shia Muslims , the entire month, Sunni Muslims,only the 10th day) as well as the issue of the "temporary marriage"? I am not implying the existance of differences ,similar to Christianity.It is well-known that heresy does not exist in Islam. If the muslim follows the five columns of faith, then there is no problem.
If i am not saying sth correctly, please correct me.