When Christ was on the earth, he organized a church with priesthood authority and priesthood offices. Jesus said: “Ye have not chosen me, but I have chosen you, and ordained you.” (John 15:16). After Christ’s resurrection and ascension into heaven, the Church continued to function, and church leaders acted with Christ’s authority to do things like determine Church policy, preach the Gospel, administer the ordinances and care for the poor. It was literally Christ’s church.
After some time, all the Apostles were killed and Christ’s authority was lost from the earth. People had the Bible, but there was no one who could speak for Christ with the same authority as the ancient apostles, and the world slipped into the dark ages.
Then, in the spring of 1820, God again opened the heavens. God the Father and His Son Jesus Christ appeared to the boy-prophet Joseph Smith. Shortly thereafter, a burst of heavenly visitations brought back the ancient church. For example, Peter James and John appeared to Joseph Smith and restored Melchizedek priesthood and the apostleship. Other angles brought ancient scripture and the authority to seal families together forever. As one might expect, Christ’s ancient and modern Church will be very similar to each other. For example, the ancient Church had 12 apostles and the restored Church has 12 apostles.. The ancient Church baptized with authority and so does the restored Church. The ancient Church preached the gospel and so does the restored Church. The ancient Church administered to the sick and so does the restored Church. The ancient Church was organized to care for the poor and needy and so is the restored Church. This literally is the Church of Jesus Christ restored in these latter days.