Are there other ways to give back to God instead of money?
Time. And that can be in a variety of ways. Feeding the homeless. Visiting or donating to people in need or struggling. Even volunteering at church.
My old church used to not pay people for anything, besides professional workers hired for certain things. But they didn't hire cleaning crews, people volunteered to keep the place clean. Some may simply vacuum the sanctuary. Others the kitchen. Watching the young kids during service.
Even if they held an event, such as something outdoors and needed things built, that was usually people volunteering, some of which were professionals.
And done without guilt or pressure. They simply asked and people were happy to volunteer.
And the few people hired to work there often were responsible for helping as well. They also only had 3 paid employees, if I recall correctly. Pastor, youth pastor and music leader. And they went many years before hiring someone for music.
And this wasn't a huge church, nor was it small. It was a good size.
Sometimes one on one helping people works also. Some people have a knack for that.
Seems the best way to serve is find out what you're skilled and care about and search out a way to put those together and utilize them that way.