After the death of Jesus’s Apostles, God’s priesthood authority was lost.
When Jesus was on the earth, He called twelve Apostles and gave them authority to preach, baptize, and lead His people. After Jesus left the earth, the Apostles continued to receive His guidance through the Holy Spirit. They worked to establish churches in the ancient cities of Rome, Greece, and beyond. But they constantly struggled to maintain order among the new Christian converts
As the Church grew, the Apostles faced dissent among believers and harsh opposition from nonbelievers. Many Apostles were martyred, and people disagreed about the meaning of Jesus’s teachings. People began forming various churches without God’s authority to do so. These churches strayed from Jesus Christ’s original Church.
As a result, Christianity experienced a widespread Apostasy, or departure from core religious beliefs. God’s priesthood, or the authority to act in His name, was lost, pure principles were corrupted, and the truths of the gospel were scattered.
In the 16th century, reformers such as Martin Luther and John Calvin recognized the fallen state of Christianity. They sought to return the Christian church to its earlier state to align more closely with biblical teachings.
However, it wasn’t enough for Jesus Christ’s original Church to merely be “reformed.” Certain principles and truths had been lost long ago, along with the priesthood authority to act in God’s name. Jesus Christ’s Church in its entirety would have to be brought back, reinstated, or in other words, restored.