The liturgical realm also was very much changed. One of the most important changes was the introduction of confirmation, the sacrament which the Reformers had thrown out and now the Pietists reintroduced, as a confirmation of the sacrament of baptism.

Pietism is especially important for theology in three points: it tries to reform: 1) theology 2) the Church 3) morals.

Theology is a practical habit. He who knows must first believe – the old demand of Christian theology. This demand brings in, at the same time, the central importance of exegesis. It is not systematic theology which is decisive, but Old and New Testament theology. And wherever Biblical theology prevails over against systematic theology, we have almost always a pietistic influence. The theologian shall first be educated to self-education, in order to be able to edify others.

The Church is a body which is not there only in order to listen to the Word; and the bearers of the Church are not just the ministers but all laymen. The layman shall have an active part in the priestly function, in different places – sometimes in the Church, but mostly in their houses, and in special collegia pietatis, colleges of piety, I. e., coming together in groups to cultivate piety. They should have hours of Biblical interpretation – they were therefore called “Stundists” , and they must drive towards conversion.

From this point of view they even introduced Presbyterian elements into the Lutheran churches. They tried to emphasize an ecclesiola in ecclesia, a small church in the large Church. And then they changed moral theology, about which I will say something tomorrow.
Paul Tillich, A History Of Christian Thought – Table of Contents