I was in kindergarten Winnie the Pooh room.
Mathew 5:34 says don't take an oath. Not sure if an oath and pledge are the same.
Swearing by my tattoo isn't the same as getting married to it so I suppose it's okay to pledge allegiance just as a sense of national identity. You can be a national of America and a national of heaven at the same time.
I have been using oath and pledge as synonyms; both, the way I use them, mean promise.
I pledge allegiance
I take an oath of allegiance