Hinduism is not a religion. Hence, you cannot trace its roots.
It is termed so, by those who wanted to depict theirs to be superior which reflects insecurity.
Whichever religion you follow you will believe in the only GOD who did not create any religion at all. GOD never asked to kill anyone because, he is so powerful that if he may wish no more, the world will demolish. Stop fooling yourself.
1. Why pharma companies bought indigenous original breed cows to use their urine & ghee in medicines?
2. Hindu people never gave any offers to join Hinduism?
3. Why does any religion does not have a way to see GOD and to know who you are?
4. Why seekers of truth land up following Hinduism – adhyatma?
Religion is a political tool.