The best systematic theologies (here I’m thinking particularly of Herman Bavinck’s) are conscious of how the doctrinalist, pietist, and culturalist impulses all grow out of the same basic Reformed theological soil. The richness of Reformed theology inevitably inspires vigorous evangelism and sound doctrine; subjective spiritual experience and the ‘great objectivities’ of the sacraments; building the church and serving in society; creative cultural engagement and rootedness in historic tradition. In actual practice, however, these emphases are very difficult to combine in a local church and even more difficult to maintain together in a denomination. The proponents of each kind ministry tend to grate on each other and mistrust each other. And yet Presbyterianism continually produces them all.--WHAT’S SO GREAT ABOUT THE PCA by Tim Keller
You need to follow the link to get the whole thing. It is a pretty amazing analysis of not just the PCA but recent Reformed church history in the USA. One of the things that warmed my heart was to find out that the beginning of the PCA there was an organization that funded revival preaching in the PCA congregations. This sort of touches back to my roots of Presbyterianism.
Source of image: http://www.valpo.edu/geomet/geo/courses/geo200/religion.html