In my capacity of rector of the historic St. innocent Orthodox Church of Eureka in Northern California, I offer a class every other Tuesday at 6 PM. The schedule can typically be found on the parish website, but it is best to call the parish phone number to check. These are typically catechism and the Bible-centered lectures that last about 25 minutes.
I also teach/preach every Sunday at the homily, which starts around 10:20 AM and which typically lasts between 15 and 20 minutes. The sermons are also posted at least once a month on the parish website and on the parish YouTube channel.
