Felt Question & Card Pics

[rissykay99.livejournal.com]

So, I have a really great idea for an advent calendar, but I've never worked extensively with felt before. I'm just wondering, if I cut a shape out of felt, do I need to stitch around the edges or will the shape stay sharp (without fraying of any kind) without stitching? For example: if I cut out an ornament, but didn't stitch the edges, will it warp/fray with time?

Thanks in advance!