In the early 1850s he got into doctrinal conflict with the leader of the movement Nils Gustaf Malmberg and got closer to the official church.

But after Essen graduated Master of Theology in 1840 with excellent grades, the Turku Cathedral Chapter decided to ordinate him.

The internal schism in the movement led to a split; Essen and many other young priests adopted Johann Tobias Beck's theology, that represented Tübingen school.

Subsequently, Essen's views approached to those of the traditional Lutheran church and participated in hymnal committee of the Finnish and Swedish-speaking versions.

His thesis is about confession and it includes a lot of influence from Beck; according to Essen, only a private penance is scripturally correct.

Carl Gustaf von Essen worked as a professor until 1875, after which he moved for retirement to Herniäinen estate in Hattula.