Although no answers were posted in the comments section of my last post, I did receive a few via email. Most thought that it was either Barth or Kant (note: these were received before I added the hint about a German who lived in the 1800s).
The answer, as you may by now know, is Ludwig Freuerbach and the text is The Essence of Christianity.
Typically in these sorts of posts I simply provide the answer to the question. But at the recommendation of my mother-in-law, I will provide a little background information about the author (taken from this wikipedia article), a brief explanation of the excerpt I quoted, and the impetus behind my selection.
Background: Feuerbach (July 28, 1804 – September 13, 1872) was a philosopher and anthropologist. He was trained at the University of Heidelberg. He completed his education in natural science at the Friedrich-Alexander-University in Erlangen. While at Heidelberg, he was greatly influenced by the Hegelian understanding of the dialectic, and he believed that Christian theology would eventually be superseded. In 1841 he published Das Wesen des Christentums (The Essence of Christianity), which was translated by George Elliot.
Explication: At this point in the book, Feuerbach is seeking to closely tie the nature of an entity with its faculties. That is, its capacity for love, intelligence, beauty, feeling, etc. He argues that a caterpillar knows nothing other than the tree which sustains it. Its understanding of its world is limited by its nature and vice versa. He sustains the parallel to humanity.
This unity between the nature of the individual and the object perceived allows him to make his case about religion and God. He argues that God is as the worshiper understands him to be. The worshiper cannot conceive of God as anything greater than his nature and understanding allow him. He also addresses the thought that what God is in and of himself differs from how we perceive him to be. He counters this with the claim that it is skepticism…the very enemy of religion. For, in so doing, we make the case that God is different than our beliefs about him, and thus, our beliefs about him are worthless.
As he gets further into the book, he explains that the virtues that humanity is capable of experiencing and expressing, unlike any other creature (i.e. love, joy, peace, wisdom, etc.) exist outside of God. God is God for the worshiper because he conforms to these virtues. That is to say, virtues are not virtuous because God possess them; they are inherently virtuous/admirable.
Why? I picked this particular quote because, though taken out of context, it addressed the very intent I had in starting this read. As Feuerbach says, “A being’s understanding is its sphere of vision. As far as thou seest, so far extends thy nature; and conversely.” I am hoping to broaden my field of vision and understanding.