We need to learn that it is healthy and okay to make mistakes.
This is key in all areas of life but really key to embrace in the fast-growing world of social media. Don't choose to ignore or hide your mistakes, instead work on them and tell your customers about it. Your customers will appreciate your openness and be touched to discover that you are working on your mistakes and trying to provide better services and products for them.
So if you make a grammar mistake on a social post like missing a simple comma, there is no need to delete the post, or even edit it. It is very likely that your audience saw your post, liked it, and didn't think twice about it. However, they will notice your continuous re-posting and editing content.
So embrace the mistakes, learn from them, do better next time, but don't fuss to cover them up. We are human.