I think that Christians have a big problem. Well, they have quite a few--this is just one of them. Their religious founders, Jesus and Paul, were Jews, and started out within the framework of Judaism. The religion, for historical reasons, has gone on to become something completely different. But they can't come out and say that, because it was created within Judaism. So they have to come up with some way to reconcile all the contradictions this creates. Does the law of the Tanakh apply to Christians, or not? Well, yes, except when it doesn't. (nowadays it seems to apply only to other people--gay people--and not whenever it might inconvenience the Christian.) So they come up with a nonsense phrase that somehow satisfies them. They can't say Jesus abolished the law, since He says in no uncertain terms He did not. So they say He "fulfilled" it. "Fulfilled" in this sentence means "did something or other so I don't have to follow it any more, without abolishing it."
They have a similar problem with polytheism. From a Jewish point of view, Christianity is obviously a polytheistic religion. But Christians cannot just admit this. For some reason they have to worship 2-3 Gods, and call it one, so they can say they're monotheistic. Again, I think this problem arises because Christianity originated as a variant of Judaism. If its founders had just made it up as a brand new religion, they could have said they have new laws, and worship 2-3 Gods. But they can't.
Because of this historical accident, in my view Christianity is flawed/dishonest/hollow at its core.