I am a Hindu but have respect to all religion.
One of my Muslim friends(my best friend) told me that ALLAH gave instructions to be followed by all. So that means if I don't follow them I have to go to hell according to Islam. Hence according to Islam is everyone a Muslim? But Hinduism is older than Islam, so how can everyone be a Muslim? I don't want to hurt anyone's sentiment, so forgive me if it hurts you. Thank you.
Everyone in this world is born on instinct to worship the only deity of Abraham. His parents make him hindu, Buddhist Christian, jew etc.
Every Human is not a muslim.
It's true that Instructions of Islam are to be followed by All. Else he will be among the losers in the hereafter.
Quran 3:85 And whoever seeks a religion other than Islam, it will never be accepted of him, and in the Hereafter he will be one of the losers.
Only Islam is recognised as a religion with Allah.
Quran 3:18 the religion with Allah is Islam.
Islam is the oldest religion of all religions. Adam and eve were a muslim couple. We are all children of Adam and eve.
It's impossible to answer, because you're asking the reverse thing.
But as a Hindu, we have story of adama and eve as well, he eat the forbidden food and they become a sinner. From the adama and eve family the noah is born, and due to flood of water, he pray to god, and god said him to go any higher mount and you'll survive with your people and then Abraham is born in noah generation. The story of noah is pretty much same like in every yuga the manu is survive by lord vishnu to keep the yugas cycle run.
Then jesus born in the womb of vergin women hence he did not inherit any sins, and said to their(mleccha) people to follow bible(and establish Christian religion), then prophet mohammad come and said people to read quran(and establish islam religion).