JACK - If God lived on an earth and progressed to godhood as we are now doing, does that mean that God possibly sinned and was in need of a savior Himself? If so, is not Jesus more perfect than His father because He progressed to godhood while in the pre-mortal existence?

JOEL - Prophet Joseph Smith said:

"God Himself was once as we are now, and is an exalted man, and sits enthroned in yonder heavens! That is the great secret. If the veil were rent today, and the great God who holds this world in its orbit, and who upholds all worlds and all things by His power, was to make Himself visible—I say, if you were to see Him today, you would see Him like a man in form—like yourselves—in all the person, image, and very form as a man; for Adam was created in the very fashion, image, and likeness of God, and received instruction from and walked, talked and conversed with Him, as one man talks and communes with another.." (Joseph Fielding Smith, Teachings of the Prophet Joseph Smith, pp. 345-346.)

Elder Orson Hyde, a member of the Quorum of the Twelve, said:

"Remember that God our Heavenly Father was perhaps once a child, and mortal like we are, and rose step by step in the scale of progress, in the school of advancement; has moved forward and overcome until He has arrived at the point where He now is." (Orson Hyde, Journal of Discourses, vol. 1, p. 123.)

And Daniel H. Wells concluded:

"God is a being of agency and He has passed along the path He wishes us to tread, and has attained to His exaltation just as He wishes us to attain to ours." (Daniel H. Wells, Millennial Star, vol. 26, p. 786.)

Despite what past church leaders have said, God really has not revealed enough on this subject to be able to answer your questions with any certainty. We don't know all the details of how our Father in Heaven became God.

Joseph Fielding Smith said:

"The matter that seems such a mystery is the statement that our Father in heaven at one time passed through a life and death and is an exalted man. This is one of the mysteries, and to some it appears to contradict other statements in the scriptures. Naturally there are many things that we will not comprehend while in this mortal life and we will not be able to fathom all of the difficulties that lie before us. Our understanding is limited and we judge according to the things we know and with which we are familiar. The things of eternity we will not understand until we reach the goal of eternal life, when all things will be made clear." (Doctrines of Salvation, Vol. 1)

What we do know is that He is the spiritual father of both us and Jesus (D&C 93:21, D&C 76: 24).
Because Jesus was first born in the spirit, the Father gave Him of His fulness which qualified Him to be called God before he came to earth (D&C 93:2-5).
But He still needed to come to earth to gain a body, die, and be resurrrected so that he could be more like his father and complete His perfection (Luke 13:32). Jesus said that he did nothing that he had not seen the Father do. (John 5:19)
If Jesus is God, yet obtained a body and lived as a mortal on an earth, then it is quite logical that His Father did the same thing some time in the eternal past.

There really is no such thing as "more perfect"; either you are perfect or not. God the Father perfected Himself in His way and Jesus in His own way. If the Father's way was to experience a life on an earth like we do, then so be it. But this does not make Him less perfect than Jesus. God the Father will always be ahead of both us and Jesus because of the glory He accumulates each time one of His children follows his example and achieves immortality and eternal life (Moses 1: 39).