With the continuing collapse of morality in our society, it will become more common for Latter-day Saints and Roman Catholics to join forces against the social ills that plague our world (e.g., abortion). While I am not opposed to such, the unfortunate side effect will be an increasing attempt at theological ecumenism, which I am completely opposed to.
The following quotation from James Talmage over a century ago captures, rather succinctly, just some of the core doctrinal problems of Roman Catholicism and why it is a false gospel (cf. Gal 1:6-9):
In her unrestrained abandon to the license of arrogated authority, the Church of Rome hesitated not to transgress the law of God, change the ordinances essential to salvation, and ruthlessly break the everlasting covenant, thereby defiling the earth even as Isaiah had foretold. She altered the ordinance of baptism, destroying its symbolism and associating with it imitations of pagan rites; she corrupted the Sacrament of the Lord's Supper and befouled the doctrine thereof by the vagary of transubstantiation; she assumed to apply the merits of the righteous to the forgiveness of the sinner in the unscriptural and wholly repellent dogma of supererogation; she promoted idolatry in most seductive and pernicious forms; she penalized the study of the holy scriptures by the people at large; she enjoined an unnatural state of celibacy upon her clergy; she revelled in unholy union with the theories and sophistries of men, and so adulterated the simple doctrines of the gospel of Christ as to produce a creed rank with superstition and heresy; she promulgated such perverted doctrines regarding the human body as to make the divinely formed tabernacle of flesh appear as a thing fit only to be tortured and contemned; she proclaimed it an act of virtue insuring rich reward to lie and deceive if thereby her own interests might be subserved; and she so thoroughly departed from the original plan of Church organization as to make of herself a spectacle of ornate display, fabricated by the caprice of man.
The most important of the internal causes by which the apostasy of the Primitive Church was brought about may be thus summarized: (1) The corrupting of the simple doctrines of the gospel of Christ by admixture with so-called philosophic systems. (2) Unauthorized additions to the prescribed rites of the Church and the introduction of vital alterations in essential ordinances. (3) Unauthorized changes in Church organization and government. Under the tyrannous repression incident to usurped and unrighteous domination by the Roman church, civilization was retarded and for centuries was practically halted in its course. The period of retrogression is known in history as the Dark Ages. The fifteenth century witnessed the movement known as the Renaissance or Revival of Learning; there was a general and significantly rapid awakening among men, and a determined effort to shake off the stupor of indolence and ignorance was manifest throughout the civilized world. By historians and philosophers the revival has been regarded as an unconscious and spontaneous prompting of the "spirit of the times"; it was a development predetermined in the Mind of God to illumine the benighted minds of men in preparation for the restoration of the gospel of Jesus Christ, which was appointed to be accomplished some centuries later. (James Talmage, Jesus the Christ [Salt Lake City: Deseret News, 1915], 748-49)
For more, see my page listing “must-reads” on the topic of Catholicism, Resources on Roman Catholicism.
Support Scriptural Mormonism