I truly believe that our Heavenly Father and Jesus Christ appeared to Joseph Smith.
Wondering which of the many churches to join, Joseph followed the counsel in the book of James in the Bible: "If any of you lack wisdom, let him ask of God." In the spring of 1820 at only 14 years of age, Joseph Smith went to a grove of trees and prayed to know which church was true.
God the Father and Jesus Christ, appeared and spoke with him.
Here are his own words describing the vision:
"I saw a pillar of light exactly over my head, above the brightness of the sun, which descended gradually until it fell upon me. When the light rested upon me I saw two Personages, whose brightness and glory defy all description, standing above me in the air. One of them spake unto me, calling me by name and said, pointing to the other—This is My Beloved Son. Hear Him!"
The Lord told Joseph "that all the religious denominations were believing in incorrect doctrines" and that he was to wait for further instructions. "In a state of calmness and peace indescribable," Joseph left the sacred grove knowing the truth of our Father in Heaven and His Son, Jesus Christ.
I believe that Joseph Smith's first vision is truly the greatest event in world history since the birth, ministry, and resurrection of Jesus Christ. After centuries of darkness, the Lord revealed His word and restored His Church through His chosen prophet. I sincerely believe this to be true.