In this article, I will seek to answer whether theological conservatism and strictness play a vital role in denominational switching, as well as what factors cause churches to grow numerically. In the end, the idea that liberal theologies cause a deterioration in mainline Protestantism, while conservative theologies produce growth, is an oversimplification of the relevant factors that account for congregational development. Though theological conservatism tends to correlate with numerical expansion, it does not do so consistently and in all cases. Nonetheless, correlation does not equate to causation. Conservatism and strictness are merely two among a myriad of other influences that are present among growing churches, including (most notably) higher birth rates, higher youth retention, and a focus on evangelistic efforts.