In the Testimony of St. John, the Samaritan woman at the well was taught about salvation by Christ. His disciples were offended that He would even speak with the woman, but the testimony we have from that encounter preserves a perfect statement of Christ’s mission.
Quoting from the 4th chapter, Christ said: “You Samaritans do not understand God, although you claim to worship Him. Those who follow me know how to worship. Salvation does not belong to the Jews, but instead will come from a Messiah rejected by the Jews. The hour has arrived when the true worshipers are being taught how to worship the Father in spirit and in truth, for the Father wants mankind to know Him. The Father will share his Spirit with those who know him. His Spirit is truth and light. And they who worship him must worship in spirit and in truth.
The woman said to him, I know that a Messiah is prophesied to come, and when he comes he will restore all that has been lost since the time of Adam. Jesus responded, I am he: I am come to restore, to repair, to redeem, and I am come to gather.” T&C 171: TSJ 4:5-6.
When Christ came to live among the Jews He was here to restore, repair, redeem and gather. When He ministered to the Nephites He was serving the same purpose. When He revealed Himself from heaven to Joseph Smith, again Christ was on that same mission.
Now, again today, Christ is working to restore, repair, redeem and gather. His mortal mission did not complete that restoration, and the faithful failed to gather to build Zion. In Joseph’s day the Lord again restored, but not fully. He also repaired, but not fully. He tried to gather, but it did not result in Zion.
Christ has explained His mission in Samaria. He has repeatedly engaged on His mission at different times and among different people. But mankind has not been willing to let Him complete the work of restoring, repairing, redeeming and gathering. It remains an open question of when the Lord will have people willing to allow Him to finish His mission.