Are you trying to bring non-active members back into the community?
Are you trying to encourage your existing, active, members to be more active?
Are you trying to build a stronger sense of community among members?
Are you trying to get members to take a specific action?
Few pointers here.
First, the newsletter is strategic. You send it out to achieve a specific goal that helps the community. If it doesn't help, stop sending it.
The answer to the above will decide who the target audience. Only send the newsletter to that audience. The answer will also determine the content of the newsletter. If you have the time, create multiple newsletters to different audience segments.
Second, pick one big action/story/element to highlight in a post, not a dozen.
Third, you don't have to stick with the same goal for every newsletter. You can rotate them. The rotation might make newsletters refreshing. However, every newsletter needs it's own specific goal.