Is Catholicism a different denomination?
By comparing the doctrines of the Catholic Church to the Bible, we can see that Catholicism is not just another Christian denomination. In fact, the distinctions between biblical Christianity and Roman Catholicism would force us to conclude that it is a separate religion.
Even though some claim the Reformation (a historical movement challenging many Catholic doctrines) has concluded, the Roman Catholic Church and its theology remain largely unchanged. The Roman Church has persisted in protecting its doctrines at all costs, condemning those who stand against them as accursed. The church still practices works-based salvation, praying to Mary, baptism as a means of justification, confession, praying the rosary, etc., all of which are unbiblical.
Unless the Roman church changes, the reformation period will continue until all the false doctrines (especially those concerning a works-based salvation) are denounced and the true gospel is embraced.
Some have argued that the Roman church has toned down its rigid approaches, but that does not change anything. The Roman church is notorious for morphing into whatever it needs to be in any nation and at any time. This includes modifying or introducing revised doctrines if needed to win people over.
This is not surprising because the devil too works in this way by shifting his methods to win people over.