He studied theology at the University of Halle, and became tutor to the eldest son of Baron von der Horst, to whose family he was attached for several years.
In 1763 he was appointed co-rector of the school of St. Martin's, and second preacher in the hospital church of the Holy Ghost, but he soon resigned these offices and followed his patron to Berlin.
Here he wrote his Neue Apologie des Socrates (1772), a work occasioned by an attack on the fifteenth chapter of Jean-François Marmontel's Belisarius by Peter Hofstede, a Rotterdam clergyman.
In this he tried to meet some objections to the former part, and continued his inquiries into the doctrines of the Christian religion, religious toleration, and the proper rules for interpreting the Scriptures.
[1] Eberhard argued in books such as Neue Apologie des Socrates that salvation did not depend upon revelation, that it was possible for a heathen to go to heaven, and that the notion of eternal punishment contradicted its supposed aim of morally improving the sinner.