This is why INDIA is secular nation in all sense,The worship of god is not restricted to any particular ritual.Hinduism means Spirituality not organisation
This is because different opinions are presented on the method of performance in different Kalpasutras. All the Kalpasutra do not give the same procedure for each achara. The explanations differ, hence the difference seen in those who are following that kalpasutra.
For example Some people celebrate Sivaratri on a particular day another group may celebrate in a different day. For one group, on the ekadasi day the srardha can be performed for another group srardha should be performed on that day. This difference is not serious. One should understand that the opinions of the Rishies vary and it is permitted.
There are hundreds of traditions and achaaras in all the countries, which are practiced on individual/ family/ society or national level, similar to the Indian traditions / achaaras. ( A non Muslim should not enter the city of Madeena/ Mecca. The picture of Prophet should not be drawn. A woman cannot become a Bishop. A pelican type of duck is forced to drink lot of water before cutting it for preparing the thanks giving day special in US and Canada . Like this there are hundreds of beliefs for all).
And so many religious books....That is the specialties and greatness of Indian culture. 1. Indians knew that the knowledge required for human beings cannot be confined to one book. Hence our forefathers presented the knowledge required in 1280 ( this may vary) foundation dharmic literature + 10,000 Sanskrit commentaries + 1,00,000 sub commentaries in regional languages
Hinduism is not a religion in true sense.It is a life style and culture of INDIANS, regardless of religion, an indian,who beleives in Indian culture can be called as hindu.