Fenderjazz. There no certain amount of time it takes to get good at playing the organ to carry a service. All that depends on the individual. We're all different and have different levels of capabilities. Example: at one time, I couldn't play the organ to save my life but I played a mean valved trombone. So one evening during a consecretion service at my church, the organist didn't show. I was the only musician there, but now I must admit, I also played the piano but not all that well. However, I got on the organ with fright in my heart, and prayer on my lips and went for the gusto. It was a hard road for me to venture, but I kept at it each night.For nine weeks. Before I realized it I was playing that Hammond B3 as if I'd been playing it all my life. So the moral to this story is , If you want to get good at something, remember to do two things at the same time, Pray and most of all, practice. It helps to have someone you can go to that will help you learn the organ. God's Blessings to ya.