Popular religion since the time of Kant and Fichte has gone in a direction they tried to prevent and that has been disastrous for the humanity both of believers and of the rest of us. Look at the role of religion in Republican presidential primaries if you need any confirmation of this last statement.
Capitalism now seems more likely a swamp, a bog, a quicksand in which humanity is presently flailing about, unable to extricate itself, perhaps doomed to perish within a few generations from the long term effects of the technology which seemed to Marx its greatest gift to humanity.
Since we cannot know too much about the long term effects of our particular lives, and since success and fame are not good measures of the value of what we have done, it should be enough for any of us that as far as we can tell, in some small way we have made humanity's future better rather than worse.
As Kant says, the contribution of any common laborer would be greater than that of the greatest philosopher unless the philosopher makes some contribution to establishing the rights of humanity.
I wish that our culture could retain the symbolism and emotional power of traditional religion while combining it with reason and science and using the combination to enhance our humanity rather than impoverishing it by choosing the one side or the other.
What Smith and Marx have in common is that they were both philosophers of great vision and perceptiveness, deep humanity, and a sense of social reality that has been lost in the abstractly formalistic economic theories that have dominated the field since the last third of the nineteenth century.