What is the minimum criteria to be a hindu?

I have a question which is that what is the minimum requirements for someone to call himself a Hindu. My father died of Cancer some years ago and since then I have never prayed to any God because I believe that there is no god. The people from different religious backgrounds tell me that he is in a better place now but as much as I knew my father I know that there was no better place for him than with me and my mother. So my question is now I am from a Brahmin family am I qualified to call myself a Hindu because I don't believe in any of it. I don't wear my sacred thread anymore, I haven't been to any temples if not for their aesthetically pleasing appearances and I am not carrying my culture forward. My father was one of the biggest God-loving people you will ever see. Never used to feel alone..said god is with us. But I am not at all like him. I understand sometimes why people hold on to god because when I feel alone. But I never go to God with any of my problems nor do I belive in Him. Does that make me not a hindu? P.S. this is not a mental health post. I am doing just fine. I am not any more troubled than a average person who lost his father a year ago.