Finding church records online from the former Russian Empire is quite a miracle. I found online the marriage record of my great-great-great-grandparents from a village near Bialystok, once Russian Empire and now in Poland. I also located church records for Bialystok that Bialystok archives does not even possess.
Latvian State Historical Archives’ Project Raduraksti has church and census records and revision lists from the mid 19th century here. The records cover these religions: Baptist, Evangelic Lutheran, Greek Catholic, Jewish, Old Believers, Orthodox, Reformed Protestant and Roman Catholic.
Not only are records from Latvia posted online, but so are records from Estonia, Belarus and Poland (the eastern area that once was the Russian Empire). The website, available in English, Latvian, Russian and German, has free registration.
Records only can be viewed on this website, which has great zoom in and out capabilities. Downloading of records is not available.
So, check out this website to see whether your family records are posted online.