The following information is quoted directly from www.lcms.org/faqs/denominations.
What are the main theological differences between the theology of Lutheran churches and Roman Catholic churches?
At the risk of oversimplification, and keeping in mind that individual Lutheran (and Catholic) theologians would undoubtedly disagree about the success of recent Lutheran-Roman Catholic dialogues in lessening or even "resolving" historic doctrinal differences between these two churches, listed below are what the LCMS would regard as some of the major theological differences between the Lutheran Church and the Roman Catholic Church:
- The authority of Scripture.
Lutherans believe Scripture alone has authority to determine doctrine; the Roman Catholic Church gives this authority also to the pope, the church, and certain traditions of the church.
- The doctrine of justification.
Lutherans believe a person is saved by God's grace alone through faith alone in Christ alone. The Roman Catholic Church, while at times using similar language, still officially holds that faith, in order to save, must be accompanied by (or "infused with") some "work" or "love" active within a Christian.
- The authority of the pope.
Unlike the Roman Catholic Church, Lutherans do not believe the office of the papacy as such has any divine authority or that Christians need to submit to the Pope's authority to be "true" members of the visible church.
- Differences remain about both the number and the nature of the sacraments.
Roman Catholics speak of seven Sacraments while Lutherans tend to speak of only two (or three). More important than number is how the Sacraments are understood. To take a single example, Lutherans believe that in the Sacrament of the Altar (Communion) Christ’s body and blood are truly present in the bread and wine of the Lord’s Supper, but they do not accept the Roman Catholic doctrine of transubstantiation, which teaches that the elements are permanently changed from the substances of bread and wine to the substances of body and blood. Transubstantiation is rejected for several reasons: It is a philosophical explanation for a work of Christ’s almighty Word which we can only believe, not explain. In seeking to explain a mystery it changes the plain and simple meanings of God’s Word (Scripture refers to the elements as both bread and wine and body and blood, 1 Cor. 11:26-27). Transubstantiation leads to the assertion that the body and blood of Christ remain present “even apart from the administration of the Supper” and so encourages veneration of the elements apart from their sacramental use and detracts from the use Christ commands: “Take eat … drink … for the forgiveness of your sins.” Lutheran rejection of transubstantiation should not in any way be taken to mean a denial that Christ’s very body and blood are truly present in the bread and wine of the Lord’s Supper for the forgiveness of sins.
- Differences remain about the role of Mary and the saints.
Unlike Catholics, Lutherans do not believe it is proper or scriptural to offer prayers to saints or to view Mary as in any sense a "mediator" between God and human beings.
While Lutherans believe any doctrinal error has the potential to distort or deny Scripture's teaching regarding salvation, we also believe that anyone (regardless of denominational affiliation) who truly believes in Jesus Christ as Savior will be saved.
What's the Lutheran response to the Roman Catholic teaching of purgatory?
Lutherans have always rejected the traditional Roman Catholic teaching regarding purgatory because 1) we can find no scriptural basis for it, and 2) it is inconsistent, in our view, with the clear teaching of Scripture that after death the soul goes directly either to heaven (in the case of a Christian) or hell (in the case of a non-Christian), not to some "intermediate" place or state.
What Scripture teaches concerning the death of the Christian is summarized as follows by Lutheran theologian Edward Koehler in his book, A Summary of Christian Doctrine:
In the moment of death the souls of the believers enter the joy of heaven. Jesus said to the malefactor: "Today shalt thou be with Me in paradise" (Luke 23:43). Stephen said in the hour of death: "Lord Jesus, receive my spirit" (Acts 7:59). Whoever dies in the Lord is blessed "from henceforth" (Rev. 14:13).
What is the Synod's belief regarding the salvation of Catholics who adhere to Roman dogma?
The LCMS recognizes all Trinitarian church bodies as Christian churches (in contrast to "cults," which typically reject the doctrine of the Trinity and thus cannot be recognized as Christian). In fact, a primary "objective" listed in the Synod's Constitution (Article III) is to "work through its official structure toward fellowship with other Christian church bodies"—which explicitly assumes that these "other church bodies" are "Christian" in nature. That does not lessen the Synod's concern for the false doctrine taught and confessed by these churches, but it does highlight the Synod's recognition that wherever the "marks of the church" (the Gospel and Sacraments) are present—even where "mixed" with error—there the Christian church is present. Such a church is a heterodox church, that is, a church that teaches false doctrine.
Of course, personal salvation is not merely a matter of external membership in or association with any church organization or denomination (including the LCMS), but comes through faith in Jesus Christ alone. All those who confess Jesus Christ as Savior are recognized as “Christians” by the Synod—only God can look into a person's heart and see whether that person really believes. It is possible to have true and sincere faith in Jesus Christ even while having wrong or incomplete beliefs about other doctrinal issues.
This explains why former Synod President A.L. Barry called members of the Roman Catholic Church “our fellow Christians” in his statement Toward True Reconciliation, which at the same time identifies and laments the false teachings of the Roman Catholic Church.
The great danger is that believing things contrary to God's Word can obscure and perhaps even completely destroy belief in Jesus Christ as one's Savior. We pray this will not happen to those who confess Jesus Christ as Savior and yet belong to heterodox church bodies, including fellow Christians in the Roman Catholic Church.