It is fair to say that most Christians, including major Christian leaders and popular TV preachers (esp. those on TBN) see the Roman Catholic Church (hereafter RCC) as merely another *Christian* denomination. Mainly due to (a) a lack of theological understanding of essential biblical doctrines such as justification, (b) a lack of understanding as to what the RCC teaches on essential doctrines, and (c) a false perception of the RCC because of the humanitarian and “good works” preformed by Catholics. What is seemly clear, unfortunately, is that most Christians have never objectively investigated nor studied the distinctive theology of the RCC (let alone studied the *fundamental* doctrines of their own faith!).
I will say at the onset, though, and as others have pointed out, there are really two categories, biblically speaking, that the RCC can fall under:
1 The RCC is a true church with significant errors, or
2. The RCC is a false church with significant truths (e.g., monotheism, the virgin birth, the physical resurrection of Christ, the incarnation, etc.).
However, anyone who has done even a cursory examination of the “official teachings” (ex cathedra) of the RCC will see plainly and in fact that the RCC rejects categorically essential biblical doctrines such as justification through faith alone and Christ as the sole means of salvation and mediation (to name a few). And, of course, they reject the sufficiency of Scripture alone. For the Catholic: the teachings of Rome are correct because Rome says they are. As seen, in 1870 (Vatican I) Pope Pius IX proclaimed: “I am tradition” and hence, the RCC’s doctrine of the infallibility of the Pope (ex cathedra) emerged.
For the Catholic, only the RCC has the authority to interpret the Bible. As Vatican II affirms, “The task of authentically interpreting the Word of God, whether written or handed on, has been entrusted exclusively to the living teaching office of the Church” (Vatican II, Dei Verbum). Catholics are taught, therefore, that only the RCC can “correctly” interpret Scripture and define tradition. Consequently, since the RCC is the *ultimate authority* there can be no higher authority or standard that can test the claims of the RCC since no higher authority can exist.
Mary of Nazareth
Scripture contains only a limited amount of information about Mary. However, she was, indeed, a very special woman. For God chose her among the women of the earth to bear the Savior, Jesus Christ. Yet, she saw herself as being in the same category with other believers, as she herself expressed, “my spirit has rejoiced in God my Savior” (Luke 1:47). She was a faithful, obedient, godly woman. Regardless of the limited biblical data, the RCC improperly exalts and even worships her, as clearly shown below. Aside from that, other Catholic Marian doctrines should be briefly mentioned (most of which developed throughout the centuries) such as the Perpetual Virginity, Immaculate Conception and Mary’s sinless life, Mary as the Mother of God, Our Queen of Heaven, Our Salvation, Co-Redemptrix, Co-Mediatrix, Our Advocate, the Bodily Assumption of Mary; etc. Mary, the object of Catholic Worship. Space precludes here to treat every doctrine of the RCC, however, some of the RCC’s key theological teachings regarding Mary should be revealed.
Many Protestants accuse Catholics of worshiping Mary, in which Catholics normally respond by saying, “Not at all, worship is to God alone, which we call latria (from the Greek verb latreuō, “to worship, honor” ), but to Mary and the saints we give “veneration,” which we call dulia” (from the Greek verb douleuō, “to serve”).
So, to avoid the charge of worshiping Mary (in the same sense as worshiping God), the RCC has developed (again, throughout the years) a doctrinal scheme that distinguishes two kinds of worship: latria (Gk. latreia) meaning, “honor,” which is to God alone and dulia (Gk. duleia) meaning, “servitude” (veneration), which is given to the saints; however, Mary is to receive “hyper-dulia,” which is the highest form of dulia. In this way, Catholics can avert the charge of idolatry when they pray to Mary and the saints and bow before statues while reciting the Rosary.
But is this distinction of between latria and dulia biblically valid? Does Scripture permit and even teach that Christians should give dulia to creatures and hyperdulia to Mary in a religious context? Absolutely not! Praying to Mary (and the saints) bowing before statues of her, giving her “hyperdulia” is pure idolatry, hence, creaturely worship. Note the following:
1. Three forms of the same thing–which is functional “worship: latria, which is the highest form of worship—reserved for God alone, dulia, which is given to saints, and hyperdulia (the highest form of dulia), which is given to Mary.
2. But, as John Calvin accurately observed, in Scripture the distinction between latria and dulia “is somewhat blurred.” (Institutes, I:12:2). Although, if this distinction is granted, then, as Calvin stated,
“it is greater to be enslaved [dulia] than to honor [latria]. For it would very often be hard for you to be enslaved to one whom you are not unwilling to honor. Thus it would be unequal dealing to assign to the saints what is greater [dulia] and leave to God what is lesser [latria]” (ibid.).
His point was clear: what is given to the saints and Mary (dulia, servitude) is of greater value than what is given to God (latria, honor).
3. Regarding idols and false gods, God commands in Exodus 20:5: “You shall not worship them or serve them; for I the LORD your God, am a jealous God.” The term translated “serve” is from the Hebrew word abad. The “most frequent English translation of the term is ‘to serve.’” In fact, both “to serve” and “worship” are translated from the same word, abad in many places in the OT. Further, the Septuagint (LXX) translates abad as both douleuō/duleia and latreuō/latreia. Thus, there no distinction made between the terms in the context of religious worship—to give dulia is to give latria.
In Galatians 4:8, Paul says, “when you did not know God, you were slaves to those which by nature are no gods.” The phrase “were slaves” (or “you served”) is from the verb douleuō. Paul was clear: “to serve” (i.e., to give dulia) anyone other than God in a religious context is wrong—it is idolatry.
Hence, when Catholics pray to the Mary (and the saints, which is clearly an act or religious worship), bow before statues, give Mary hyperdulia, etc., they are doing the very thing in which God prohibits. Thus, we must see Catholics as men and women in need of evangelism. Aside from rejecting Christ alone as the sole means of salvation, justification through faith alone, and Scripture alone as the sole authoritative rule of faith, Catholics engage in creaturely worship.
Although Catholics, in their mind, do not give Mary “worship” reserved to God alone. However, by giving her so-called dulia, that is, hyperdulia (hyper-service/enslavement), they functionally give her religious “worship,” which is reserved for God alone and prohibited by God, who commanded His people:
“You shall not worship them or serve [Heb. abad] them; for I the LORD your God, am a jealous God” (Exod. 20:5).
“When you did not know God, you were slaves [douleuō] to those which by nature are no gods” (Gal. 4:8).
 There are other issues that influence many Christians to assume automatically that the RCC is a true Christian church. For example, Mel Gibson is applaud and thus assumed as *Christian* by many Christians and prolific Christian voices such as James Dobson for his recent movie, The Passion. But Gibson is a *traditionalist* Catholic. “Traditionalists” hold strictly to only Vatican I rejecting Vatican II (1962) mainly because of various changes implemented by Vatican II. However, they hold tenaciously to the same heresies as that of the modern RCC (esp. Marian worship, rejection of justification through faith alone, etc.) and affirm the pre-Vatican II RCC’s teaching that “there is no salvation outside the RCC” (extra Ecclesia, nullus salus): “There is but one universal Church of the faithful, outside which no one at all is saved” (Pope Innocent III, Fourth Lateran Council, 1215); “We declare, say, define, and pronounce that it is absolutely necessary for the salvation of every human creature to be subject to the Roman Pontiff” (Pope Boniface VIII, papal bull, Unam Sanctam, 1302).
 Ex Cathedra (lit., “from the chair) was proclaimed as Catholic dogma in 1870. See Pope Boniface’s statement above.
 See note 2 above.
 *Tradition* is basically the writings of the early church Fathers. Even though there existed thousands of traditions many upon which were in disagreement among church Fathers (such as the Matt. 16:18 interpretation), Catholics must believe without question (fides implicita) how Rome defines tradition. Further, the RCC teaches that “Both Scripture and Tradition must be accepted and honored with equal sentiments of devotion and reverence” (Catechism of the Church, para. 82).
 Example, the Catholic doctrine of the Assumption of Mary was not officially pronounced (ex cathedra) until 1950!
 Accurately explaining the official Catholic teaching regarding Mary as Our Queen, Our Life, Our Hope, Our Mediatress, Our Advocate, and Our Salvation, etc., St. Alphonsus Ligouri, who was a “canonized saint” designated as a “Doctor of the Church” writes in his renowned book, The Glories of Mary:
for as angels and men . . . are subject to the empire of God, so are they also under the dominion of Mary” (36).
There can be no doubt . . . Mary was made mediatress of our salvation. . . . St. Bonaventure says that Mary is called “the gate of heaven because no one can enter that kingdom without passing through her . . . . Go to Mary, for she will intercede for thee with the Son. . . .” (160, 201).
the clients of Mary will be saved. . . . And St. Bonaventure [says]: “He who neglects the service of the blessed Virgin will die in his sins.” Again, “He who does not invoke thee, O Lady, will never get to heaven” (210, 221-22).
Both Vatican I and II confirm these Marian teachings. For example, a major document that come from the Second Vatican Council (1962), entitled, Lumen Gentium, the Dogmatic Constitution on the Church, proclaims in unambiguous terms these outrageous Marian doctrines (viz. sections fifty-second—sixty-ninth) such as when Mary was “Taken up to heaven . . . by her manifold intersession continues to bring us the gifts of eternal salvation. . . . Therefore the Blessed Virgin Mary is invoked in the Church under the titles of Advocate, Helper, Benefactress, and Mediatrix” (sec. 62).
 Latreia (latreian) is translated as “service of worship” (NASB) in Romans 12:1.
 Cf. James White, The Roman Catholic Controversy, 210).
 The English translators determine whether to translate abad as “to serve” or “worship.” For there is no difficulty understanding the meaning in Hebrew—both “to serve” and “worship” are united under the same term—abad, “you cannot separate the two” (ibid.). In Exodus 20:5 of the LXX (see note below), the term “serve” is from latreuō—thus, both latria and dulia mean the same thing (esp. in religious contexts).
 The Septuagint (LXX) was the Greek translation of the OT.
 The noun being duleia.
 Of course, there are places in Scripture where men honored and served others, but it was never in a religious context. For when Cornelius bowed before Peter, Peter rightly stopped him saying, “I too am just a man” (Acts 10:25-26).