By default, any member can post anything they want in your Facebook Groups. This means they could post horribly offensive content, and while you can remove it, it might be a while before you get to it.
If you want to play it safe, you can set your group so that every comment has to be approved by a moderator. Here’s how.
Go to your Group, click on the three dots and select Edit Group Settings.
Scroll down and under Post Approval, check the box that says All Group Posts Must Be Approved By an Admin or a Moderator, then click Save.
Now when someone posts in the group, you’ll get a notification that a post needs approval.
Click on it to go to Pending Posts.
Click the checkmark to approve the post, the X to remove the post, or the circle to block the poster and remove the post.
Once you approve a post, it will appear on the page as normal.