Why would God need a 'manifestation' when he can do it directly? Does God need help? A long time back, at about post 300. I gave you my particular Hindu view, which is that all souls are on a continuum of evolution/maturity. So from that POV, after several lifetimes, you too can be a Baha'ullah. (Not that I personally think Baha'u'llah was all that great. I thought the answer he gave to the people who asked him how old he was was silly. A wiser man would have just given his age, so the adherents wouldn't have to argue/discuss/debate for any longer. Seems to me he was causing more problems with that answer, rather than solving any, lol.)
Remember, Hindus also have holy men, and lots of them for all the various schools. The difference is we don't credit them with as much power as prophet based religions do, and we take more of the work upon ourselves to figure things out, believing the only true knowledge is what we realise on our own. Almost all of our holy men and women are celibate monks or nuns. (There are some exceptions, in some schools, but its not as common.) The rest is someone else's so all we can do is regurgitate it, as Baha'i's seem to be very fond of doing, although Adrian, and now you, have cut back on the quoting a lot, which I'm personally grateful for.