In the New Testament it openly calls him a god, son of god and messiah in one (in John) and ordinary Christians the world over pray to him as their “lord” regularly.
You can argue, though, that it is not Avoda Zara. Tosafos in Sanhedrin seems to say that even though when they mention G-d, they are referring to Oisoi, they mean the One that made the heavens and earth. This means that although their belief is Kfira as to the who Hakadosh Bauch Hu is, nevertheless, it still is not Avoda Zara.