I actually knew a little more about my family in Germany than what you have given; i.e., you haven't stated a home town.
Our family came from Westphalia, Prussia, but the important thing is that the LDS church micro- filmed most of the church records in Germany. In our case they microfilmed the records for the churches that both sides of my family went to, hence, their birth, baptisms, parents of children, etc. are all there in the IGI files.
Now those files are not perfect. All they have in the computer file is what some volunteer transcribed from the microfilm based on a standard format; so if you are a serious researcher, you need to view the film itself and record the sponsors, witnesses, etc. All of this will help you to expand your German family.