While many responses to the Pew Report seem to suggest religion boils down to whatever a person wants to believe, or whatever a person wants to make God, or whatever combinations or attractions work for a specific person, (or don't work for a specific person), it should be noted that:
While idolatry is nothing new, true religion is not about man determining God, but man responding in relationship to the God who is.
While polls and reports may provide a picture of the religious landscape... and even shape the greater future landscape when it comes to things like politics, public policy, persuasion, etc., they do not change or retard but rather serve the work of the kingdom of God, as it matters not how many choices or changes unbelievers might select, exchange or convert from in their unbelief, but that God according to his timing and pleasure calls, converts and recreates the elect through new birth, regeneration and sanctification. While polls mean much to the world, and can be useful to some extent for man, one must not forget what matters most is the ongoing and unstoppable work of God who through the church is continuing to grow the body of Christ even in the midst of a changing and foundationless world.
Even as we know the certainty of the things of God, as the tides here on earth seem to come and go, we can be certain that the trends as we see them now will not continue forever, and who knows what the backlash or response will be ... either toward the things it has moved from, or to things altogether new, but this much we can be thankful for...
The present trends can be healthy and helpful to the true church in these ways: in identifying those who in the past may have been disguised under the cloak of religion though inwardly they held to unbelief, and in better distinguishing the true church from others as unbelievers experience and exercise greater freedom in expressing their own beliefs and practices.