It is true that people today are in specific religion because their family had choose it for them. This is not Spiritualism.
True Spiritualism can only occur when a person study all the religions and choose the one he wants to follow by his own free will.
And No, I don't believe that following Atheism will bring Man toward betterment. One cannot improve oneself by degenerating oneself back to the animalistic state which humans evolve from.
“I distrust those people who know so well what God wants them to do, because I notice it always coincides with their own desires.” -Susan B. Anthony, 1896