I am a Hindu. I want to share some insights I have got with people who consider themselves non-hindus. Everyone is welcome.
In Hinduism there isn’t a specific messiah or guru who preached Hinduism. It is believed that every person born is a part of the omnipresent Collective consciousness who is better known as the God. The concept of a propagated, preached or followed religion does not exist. To be precise even the name Hinduism is foreign to Hinduism itself. It is so vast and so open that anyone or everyone is by default a part of this movement. It is as natural as being a human. It is a part of your being, no matter who you believe yourself to be you are one of us. It is vast enough to let anyone believe in any God as such and yet be in the folds of Hinduism. Because it is a part of your being. It has such depths of knowledge that you could dig all day through arguments and yet never find a bottom to its spirituality. Yet at the same point you could find a place of solace if you want to. The rituals and surfactant beliefs which are thought to be the Hindu religion by praticing hindus and others are just some adopted practices. Actual pure Hinduism is too huge and large to care about whose caste is what. Believe me those are just some practices adopted by people out of ignorance. A parallel can be drawn if you refer to Christianity where concepts of Infidels and Godless (similar to lower caste) exist. Christ wanted to take people together not divide them, division was done by people who claimed to follow him. Just like that people adopted some malpractices over the hundreds of centuries. That does not undermine the greatness or Glory of Hinduism by any measure. On the contrary imminent research and rediscovery of the ages old yet timeless and relevant for all times knowledge is the need of the hour. To the believers of other religions, I say it might be told in your scriptures that all others except yours are untrue and should be shunned so you may oppose me. But let me assure you Hinduism in its original form actually accepts your belief as it is. It isnt your opposite, it is yours should you choose to open your eyes and see. Practice your own belief as you deem fit but do take a dive in this Vast universe of knowledge. I am sure everyone will find something of use.