What does the Bible say about the origin of the church?

The Bible indicates that the church has been in existence since the beginning of Jesus' earthly ministry. Jesus called the apostles during this time, establishing them as the foundation of the church. The practices of baptism and the Lord's Supper were already being conducted before Pentecost, as shown in passages like Matthew 28, where Jesus gave the Great Commission to the apostles. Therefore, the church was not an institution that began at Pentecost but was already a functioning entity during Jesus' ministry.