I think as humanists we are far more likely to succeed as religion reformers, or religion modernizers if you will, than we are to succeed as religion exterminators.
Religion is an idea born of the human experience. Like any really successful idea, religion has outlived its various creators. Religious ideas have taken on a life of their own. But the human origins of ideas like God, don't make these ideas worthless and invalid. There are lots of other human ideas, the value of which none of us would question. Ideas like democracy, freedom, equality, fairness-----none of these things exist in nature. You can't pluck democracy off a tree, mine freedom from the earth, or spy equality among the stars. They are all human inventions, all human ideas, of such importance that they have taken on a life of their own. They live and evolve through human culture. Right alongside the ideas of religion.
Western democracy was born in ancient Greece and nourished in ancient Rome, but we would hardly recognize what they considered democracy to be. The idea has evolved. So too have ideas about God. God's evolution has been from an external sky God to an internal abstraction. But the idea, the human idea of God, has not ceased to be important in the progress of human culture or in the lives of individual human beings. When I think about the concept of God as something that sits within us, I am referring to love, to order, to beauty, to those characteristics of nature that inspire us to our best selves. I don't mean a sky God. Certainly, there are some who still think in terms of a sky God, and who will go on doing so. But let's be honest, many of them are the same people who don't know Einstein or Darwin, who haven't heard Bach or Coltrane, and who haven't a clue how to make use of a parable.
Humanists are apt to say when it is time to move on. Recognizing the human origins of all human ideas, humanists are apt to say when an idea's time has come and gone. When it is time for an idea to evolve.
Though I am pessimistic about ever ridding humankind of religion, and indeed I am quite dubious about the value of doing so, I am sanguine about the possibility of humanists and naturalists being able to help in the evolution of traditional religion in the direction of something capable of making sense in the modern world. I think we have a far greater chance of success and a far greater opportunity to impact human civilization for the good if we take up the challenge of modernizing religion rather than banishing it to the scrap pile of history.