Ideally a child should be informed in unbiased and rational way about the different world views and spiritual/philosophical positions in the world, and then be allowed to form his or hers own opinion.

but as we know the world is not perfect and this will not happen......religion and dogma is too engrained into our societies for it not to affect a child.

as for mental abuse?....I think you can find examples where I would use that world, like people that have extreme religious views and push that on their children causing them to live lives that are limited in so many ways....
But the average non-fanatical religious person that raises his children acording to his faith...I wouldn´t call that abuse....that´s an exageration.

Myself I was raised as a catholic, I was baptized, did first communion.....I don´t think I was mentally abused.....hey I even went to school in a catholic school for 4 years (and I wasn´t abused there either ) but when I got to the age I could think clearly about it I threw the religion aside pretty easily and became more of an atheist

In summation....moderate religious upgringing is no more mental abuse than telling a child there is a Santa Claus or a easter bunny.....or reading them Grimm's fairytales.