In the past year, I've seen an assortment of articles detailing Generation Y's relationship to organized religion. Nearly all of them have the same verdict: Millennials are leaving the Church in droves. Although there are multiple reasons attributed for the phenomenon, there is a general consensus that Millennials are dissatisfied with church teachings on social issues, and thus are unable to reconcile the popular post-modern worldview with what they perceive to be antiquated religious morals.
I use "popular post-modern worldview" to describe contemporary socio-cultural thinking. While not characterized by one generalized maxim, this worldview is saturated with concepts like social justice, equal rights, humanism, science, and the like. From a more practical standpoint, we've seen this play out in a variety of co-related movements: reproductive rights, marriage equality, evolutionistic thinking, etc.
The real tragedy here is not so much that Millennials are distancing themselves from the Church*, but that they have already adopted worldviews dramatically inconsistent with the biblical paradigm. What wholly matters to them is not giving pleasure and glory to God, but rather meeting the needs of humanity. There is also a prevalence of the fallacious "it's old, so it's wrong" ways of thinking. For even those who have claimed a limited degree of religious affiliation, God-centeredness has been so relegated to a secondary position that there really is no gospel reality in their lives.
Millennials prone to toss out the totality of the biblical gospel because of disagreement over social implications of scripture reflect the tragedy of the unregenerate heart. When an individual leaves the church over a social matter like abortion, it is evidence that they were never there to hear the saving and atoning work of Jesus Christ in the first place. And some Millennials, instead of taking the guilt-ridden path of abandoning religion entirely, are flocking to liberal churches which propagate agendas consistent with their worldviews but are Christian in name only.
It is important to note that the gospel of Christ does not revolve around social matters and is thus not mutually exclusive with them. In fact, I believe there are biblical commissions to further some areas of social justice (James 1:27). Furthermore, it would be wrong to assume that the primacy of Christ's work in the gospel is an excuse to renege on our obligations to live out compassion and love for others (Romans 12).
However, it is of utmost importance to uphold fidelity to the scriptures, ensuring that the gospel is not compromised, particularly in light of contemporary secularism. There seems to be an implication that if churches want Millennials back, then they'll have to tweak a few teachings or abandon certain doctrines. Yet the Bible is utterly clear that woe be unto churches which take this road of compromise, effectively distorting the true gospel and promoting a false one.
Today, mainstream evangelical Christendom is saturated with churches that either teach aberrant theology (i.e., prosperity gospel, charismatic doctrines) or no theology at all (i.e., Methodist and Episcopalian denominations in particular). While these churches are vastly different in nature, they both cater to the seeker-sensitive worldviews of its congregants, giving people what they want to hear and tickling their ears (2 Timothy 4:3).
The real question is not what churches should do to gain Millennials back, but how faithful they are in promoting the gospel of Jesus Christ. Churches must strive to avoid seeking to fill the pews with warm bodies but cold unregenerate hearts. We should instead be concerned with fidelity to the Word. God, in His sovereignty, will do the rest.
*The shock aspect of evangelical reaction to the Millennial exodus is also indicative of attendance as a preeminent factor in indicators of church success. Sound biblical churches should be much less concerned of number of congregants (Millennials or otherwise) and much more concerned about preaching the truth of the gospel.