believing in islam also means rejection of taghoot and all false idiologies, anyone who claims another way of life is a kaffir by their actions and speech no matter what they feel is in their heart.
this is the meaning of imaan, what is in the heart, what is confirmed on the tongue and what is shown through actions.
anyone who has hindu on their id is a kaffir and there is nothing wrong with saying so, rejection of disbelief is part of our imaan, one of the conditions of the shahadah, al-wala wal bara
Hmm well last friday i was listening a beautiful recitation of the battle of Uhud. And one of the shaheeds was a Jew, who didn't say shahada, or offer one rakat of prayer or changed the "religion" on their name tag.