Your goal as a church should be to write something for your website each week. ON the website, since Facebook posts don't really count in the same way. And since the goal is to update the website weekly, that means you should have a new article each and every week. If you're lucky enough to have a few volunteers, then make it the goal to have a few sections updated each week. The point is that, for most churches, the weekly goal really starts out as monthly, and then it eventually becomes yearly. Yes, I have seen this quite a bit. You might see it as a hassle, and added commitment, or even as a great opportunity, but you have to do it if you want your website to help your church.
Without the weekly content, your website is basically an online business card. While that's not terrible (and Luthernet will still build you a nice one), it's also not terribly effective at getting new people to discover your church. Your current members will also realize that there's something new to read each week. Even if you write only a couple of paragraphs and don't have a whole lot new to say, you should continue to add content each and every week.