It most certainly is a denomination and became so when it wove pagan rites and rituals into it's doctrines and twisted scripture to accommodate worldly pagans and their practices.... Just as it continues to do today via Pope Francis in embracing Islam and other pagan religions....just as the former Popes of History who aligned with the Worlds Governance's and False religions of their time....None of which is the Church of the Bible nor Biblical Christianity.
The True Church is made up of the body of believers regardless of their denomination or affiliations. Salvation and living a Christian life is not dependent on a denomination...it's dependent on a relationship with Jesus Christ.
“It most certainly is a denomination”
Nope. Christ’s Church - the Catholic Church - can never be a denomination.