There is no gaurantee that when a Hindu is death, it will born as a Hindu in next life. Like wise there is no guarantee that a Budhist will born as a Buddhist or Muslim will born as a Muslim in next life. Anyone can born as Hindu, or Buddhist or Muslim after death. I may be be born as Hinddu or Muslim or Christian or Buddhist etc in my next life. So, it is foolish on my part to hate or fight with others.
It is indeed foolish to fight on religious issues. Almost ninety nine per cent of the people adopt the religion of their parents and in rebirth, nobody knows to parents of which religion we will be born again.
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According to Hinduism all are basically Hindu.
Rebirth to other religion theory is diluted here.
Rebirth is there and rebirth takes place within the mother religion.
Hence fighting in the name of different faith is mortally foolish.