Most research confirming a connection between conservative theology & growth is flawed, because it does not account for the fact that some liberal churches are growing, while some conservative churches are in decline, & the fact that the more conservative a congregation, even though it may grow quickly in the short run, the more likely it is to fragment in the long run.
A closer look at the data on church growth shows that what actually is associated with church growth is a clear congregational vision, a focus on relationship with God & the body of Christ, radical welcome, & a missional mindset.
In addition, church demographic trends suggest that, with the fragmentation of churches and denominations at rate exceeding the growth of the Christian population worldwide, any growth seen today will be short-lived, and that churches and denominations will become unsustainable by the end of the century.
For more, click here: http://faithx.net/faithx-research-the-religion-singularity/