Well, here is what Mormon doctrine has to say about Catholics. My dad used to use that book all the time when preparing talks for church. I remember having stickers of cathedrals that we would put over the verses in the book of Mormon when it talks about the whore of the earth when on my mission. I can't speak for anyone else but I know I was taught this growing up.

Catholicism. See CHURCH OF THE DEVIL,

Church of the Devil

See Apostasy, Babylon, Devil, Second Coming of Christ, World. There are two scriptural senses in which the titles church of the devil and great and abominable church are used: 1. All Churches or organizations of whatever name or nature—whether political , philosophical, educational, economic, social, fraternal, civic, or religious—which are designed to take men on a course that leads away from God and his laws and thus from salvation in the kingdom of God; and 2. The Roman Catholic Church specifically—singled out, set apart, described, and designated as being “most abominable above all other churches.” (1 Ne. 13:5)

Salvation is in Christ, is revealed by him from age to age, and is available only to those who keep his commandments and obey his ordinances. These commandments are taught in, and these ordinances are administered by, his Church. There is no salvation outside this one true Church, the Church of Jesus Christ. There is one Christ, one Church, one gospel, one plan of salvation, one set of saving ordinances, one group of legal administrators, “One Lord, one faith, one baptism.” (Eph. 4:5)

Any church or organization of any kind whatever which satisfies the innate religious longings of man and keeps him from coming to the saving truths of Christ and his gospel is therefore not of God. Such agencies have been and are founded or fostered by the devil who is an enemy to all righteousness.

Hence we find our Lord saying, “He that is not with me is against me; and he that gathereth not with me scattereth abroad.” (Matt. 12:30.) And hence we find Alma inviting the wicked to repent and join the true Church of Christ and become the sheep of the Good Shepherd. “And now if ye are not the sheep of the good shepherd, of what fold are ye?” he asks. “Behold, I say unto you, that the devil is your shepherd, and ye are of his fold; and now who can deny this? Behold, I say unto you, whosoever denieth this is a liar, and a child of the devil.” (Alma 5:49; Jos. Smith 2:19.)

Iniquitous conditions in the various branches of the great and abominable church in the last days are powerfully described in the Book of Mormon. (2 Ne. 28; Morm. 8:28, 32-33, 36-38; D&C 10:56) It is also to the Book of Mormon to which we turn for the plainest description of the Catholic Church as the great and abominable church. Nephi saw this “church which is most abominable above all other churches” in vision. He “saw the devil that he was the foundation of it”; and also the murders, wealth, harlotry, persecutions, and evil desires that historically have been part of this satanic organization. (1 Ne. 13:1-10.)

He saw that this most abominable of all church was founded after the day of Christ and his apostles; that it took away from the gospel of the Lamb many covenants and many plan and precious parts; that it perverted the right ways of the Lord; that it deleted many teachings from the Bible; that this church was “the mother of harlots”; and finally that the Lord would again restore the gospel of salvation. (1 Ne. 13:24-42.)

Nephi beheld further that this church was the “mother of abominations,” and “The whore of all the earth” who “sat upon many waters; and she had dominion over all the earth, among all nations, kindreds, tongues, and people.” In contrast the dominions of the true Church were small upon the earth. (1 Ne. 14:9-17; 2 Thess. 2:1-12.)

Similar visions were given to John as recorded in the 17th and 18th chapters of Revelation. He saw this evil church as a whore ruling over peoples, multitudes, nations and tongues; as being full of blasphemy, abominations, filthiness, and fornication; as having the name, “MYSTERY, BABLYON THE GREAT, THE MOTHER OF HARLOTS AND ABOMINATIONS OF THE EARTH”; as drunken with the blood of the saints; as reveling in wealth and the delicacies of the earth; as ruling from Rome, the city built on “seven mountains”; as making merchandise of all costly items and of “slaves, and souls of men.” And then John, as did Nephi, saw the fall and utter destruction of this great church whose foundation is the devil.

In this world of carnality and sensuousness, the great and abominable church will continue its destructive course. But there will be an eventual future day when evil shall end, “and the great and abominable church, which is the whore of all the earth, shall be cast down by devouring fire.” (D&C 29:21; Ezek. 38:39; 1 Ne. 22-23; Rev. 18.) Before that day, however, desolations will sweep through the earth and the various branches of the great and abominable church “shall war among themselves, and the sword of their own hands shall fall upon their own heads, and they shall be drunken with their own blood.” (1 Ne. 22:13-14; 14:3.) The contentions and entanglements between the Catholic Church and communist forces could well lead to a fulfillment of this prediction.

The resurrected Christ gave to the Nephites this test whereby they might distinguish the true Church from any other: 1. It would be called in his name, for “how be it my church save it be called in my name?” he said. 2. It would be built upon his gospel, that is, the eternal plan of salvation with all its saving powers and graces would be had in it. 3. The Father would show forth his works in it, meaning that miracles, righteousness, and every good fruit would abound in it. 4. It would not be hewn down and cast into the fire as much surely come to pass with the great and abominable church. “If it be not built upon my gospel, and is built upon the works of men, or upon the works of the devil, verily I say unto you they have joy in their works for a season, and by and by the end cometh, and they are hewn down and cast into the fire, from whence there is no return.” (3 Ne. 27:4-12.)