It was a religious division in the Christian community between the Catholics in the west and Orthodox in the east. The Catholics accepted the authority of the pope and the Orthodox did not. The year the formal split occurred was in 1054, but there were multiple disputes growing before the grand split. One primary reason for the split was that Rome claimed to have the most authority and jurisdictive powers in the Christian community on earth because Peter had died in Rome. Rome claimed Peter had passed the “keys” to the “kingdom” to people in Rome giving them authority. The Church in Constantinople claimed it was more influential, rich, populated, and powerful so it should have authority at least equal to Rome. Some more problems were the language barrier, practices, and customs.
The sacraments are sensible signs of God’s invisible grace. The sacraments were either visible, audible, or physical. God’s grace was His life and love flowing into the soul. A good example of a sacrament is baptism. When we are baptized we can’t see, hear, or physically feel God’s grace moving into us, but we can see the water.
An indulgence was a gift from the church to someone who had done a good act. If you sinned and did a good deed the church could partially or fully remove your temporal punishment on earth. This was an indulgence.