Welcome! I am ELCA but former Catholic. Some of the main differences you will be familiar with. Lutherans do not pray to saints, believe in the Real Presence but not in the same way as Catholic, do not believe in the papacy, and LCMS do not have an episcopal church structure or apostolic succession. There are more in depth theological and superficial differences, however they have lessened somewhat over the years as Rome has moved away from many of the medieval practices that were partially the cause of the Reformation as it was.
You will hear things like "Catholics believe in works salvation" but that is not entirely true to the Catholic theology. Overall there is much overlap in beliefs, but still some ground to cover if there ever is to be a common communion between the churches.
Both churches believe in the Real Presence in the Eucharist. Here is a pretty good overview from a Catholic source (bustedhalo):
What’s the Difference Between the Catholic and Lutheran Belief in Communion?
Crash Course History does a good (and entertaining) overview of Martin Luther and the Reformation:
This is from the
LCMS website:
QUESTION: What are the main theological differences between the theology of the Lutheran Church and the Roman Catholic Church?
ANSWER: 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:
1. 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.
2. 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.
3. 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.
4. 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.
5. 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.