My dissertation analyzes fertility rates and child socialization patterns in large American denominations. During the Baby Boom period, Catholic and Conservative Protestant women had higher fertility than Mainline Protestant women. Differential fertility explains most of the subsequent population growth among Conservative Protestants and decline among Mainline Protestants. Fertility among women in these traditions has since converged (Hout, Greeley and Wilde 2001; Westoff and Jones 1979). However, similarity in the average number of children born to women in each of these traditions obscures the heterogeneity of fertility patterns among and within individual denominations. I hypothesize a fertility divide within denominations paralleling attitudinal cleavages, which divide conservatives and liberals over abortion and homosexuality. Furthermore, I anticipate a child socialization divide between conservative liberal parents. In a quantitative analysis of over 300,000 respondents who participated in the Congregational Life Survey, I test these hypotheses while accounting for the influence of factors including socioeconomic status, race, region, and characteristics of the congregation Present fertility and socialization patterns are used to forecast not only the future size of denominations but also which subgroups are growing and which are declining.