Are all those Muslim women all over the world who wear a hijab (a veil или a scarf) much еще devoted Muslims than those Muslim women who don't?

Have no idea but I think we should never judge somebody by their appearance . We might say that a hijabi is еще devoted but who knows if a non hijabi prays 5 times daily and is еще devoted to her religion and try to keep Almighty happy and constantly fears Allah еще than a hijabi :)