Let’s look at some of the things that can negatively affect the quality of your stream.
Cameras typically do not have the same range of "vision" as the human eye.
They over-expose far before your eye would, and they can't see the same levels of blacks that your eye can. So, your cameras need less variation in your lighting to create a nice picture. I.e., you need to have less contrast in your lighting.
You should make sure that the background of your stage, especially the space that you pick up when you're zoomed in on the pastor for preaching, is appealing on video. A big, black hole isn't great as a video background.
Your connection to your CDN needs to have dedicated bandwidth, and reliable bandwidth.
This is either through a separate internet connection, or through routers that can give priority to your stream's upload and "starve" other internet users if needed to ensure that the stream bandwidth isn't interrupted.
You don't need a bunch of teens firing up their online games in the youth space taking down your service stream.
ISP needs to provide consistent, reliable service.
The biggest comment I've heard from people describing their streaming issues is having that reliable connection to their CDN.
A question posed to me from a previous article asked about dealing with audio dynamic range issues for their stream.
In the auditorium, you can have as much as a 30dB difference between the band and the spoken word. If you simply take the feed to your PA system and use that for your stream, when your viewers have the music at a reasonable listening level, the spoken word parts will be inaudible.
You need to boost the spoken word inputs much closer to the band levels in your audio feed to your stream.
This can be done via a matrix mixing section of a larger front-of-house audio mixer, or by using group outs of your main console (a group for band, and a group for spoken word) feeding into a small mixer to bring the spoken word channels up to a level much closer to the band.
Another point is that if you're going to do streaming, do it well.
I've watched a variety of church streams, and there are some that I'd never go visit that church after watching their stream, because their stream made them look terrible. The in-person experience might be a lot better, but I'll never find that out. Their awful video stream at the very least moved them to the bottom of the list of churches to visit.
To wrap up, I'd suggest that you ask yourselves why you want to stream. It can be costly, it takes more volunteer resources, and generally results in very few viewers.
If you're already doing live video in your services, it's not that big a leap, but if it's all new to you, it's a big commitment.
Many churches I've talked to don't have that many viewers, and a decent percentage of the viewers they do have are people who decided to stay in their pajamas instead of driving to church. Of course, there are others with a large viewership, but I don't think that's the norm.