I agree that the differences between Lutherans and Catholics can appear subtle, but the differences were significant enough to split the Church.
The liturgy looks very similar. Many times there is only a word or two different in our prayers. Catholics celebrate Mass daily, while in the Lutheran church the frequency of communion services is left up to the individual parish. They typically follow the readings for the church year that is almost exactly like the Catholic church readings. The church calendars are almost identical, with a few significant exceptions.
The number of sacraments is different. Catholics have seven sacraments, while Lutherans only have two. Lutherans believe in the real pressence in the Eucharist, but the theology and terms we use are different. We both baptize in the name of the Father, Son, and Holy Spirit. The Catholic Church also believes that confirmaion, confession, annointing of the sick, marriage, and holy orders are sacraments. Lutherans may have those things, but don’t call them sacraments.
Church authority is the main difference. The Catholic Church, as recent events highlight, has the Pope as the earthly authority to guide the Church with the aid of the Holy Spirit. Catholics believe the Christ guaranted protection of the Church’s doctrine when He told Peter, “the gates of hell will not prevail.” (Catholics do not believe that those who separated themselves from Peter’s successors during the Reformationhave that same protectionof their doctrine, and we see multiple conflicting doctrines among the Protestants.)
After Luther left the Catholic church, he set up an organization that looks remarkably like the catholic church without a pope–Lutherans have bishops too. But Lutheran bishops aren’t united with Rome, and many aren’t united with each other. You probably are aware of the various synods who interpret Lutheranism different among themselves. Authority in the Lutheran church depends on what synod you belong to, and in some their church doctrines are voted on in conferences.
We also understand different meanings in the phrase “Communion of Saints” in the Nicene Creed. Catholics believe that the saints in heaven can help us to Jesus. Just like all the good Pope John Paul II did in his life is now showing many people what a Christian life can look like, the saints show us how to follow Jesus. Catholics don’t believe they stop doing that just because of death of the body–their souls are alive with Christ and we believe they can continue to pray to Him for us, just like they did on earth.
On social issues, such as abortion, the Catholic Church and some of the conservative Lutheran synods (i.e. Missouri synod, Wisconsin synod) hold similar positions. More liberal synods (like the ELCA) share some similsr issue with social justice, but not on abortion.
Okay, this is a realy long post. You can probably guess I had ties with the Lutheran church. I used to attend a Lutheran church with my husband. My husband and dad were converts to Catholicm from Lutheranism. I know many wonderful Christians who are Lutheran. But I believe the Cathlic church has the fullness of the faith and the protection promised by Christ to Peter. I once heard a Lutheran pastor say that Luther’s original 95 points have been addressed in the Catholic Church. I invite you to learn more about the Catholic faith.