Is there Such a Thing as Pre-Existence as Taught by Mormons?

Did humans pre-exist in heaven with the Father? Adam was not a living being until after he was created by God.

"And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul" (Gen. 27).

Were we spiritual bodies before we entered into the flesh? Why can't we remember ourselves as pre-existing?

"Howbeit that was not first which is spiritual, but that which is natural; and afterward that which is spiritual. The first man is of the earth, earthy: the second man is the Lord from heaven" (1 Cor. 15.46,47).

Have Mormons seen the Father in a pre-existence?

"And the Father himself, which hath sent me, hath borne witness of me. Ye have neither heard his voice at any time, nor seen his shape" (John 5.37). "Not that any man hath seen the Father, save he that is from God, he hath seen the Father" (John 6.46). "Jesus said unto them, If God were your Father, ye would love me: for I proceeded forth and came from God; neither came I of myself, but he sent me" (John 8.42). "So Jesus proclaimed, as he taught in the temple, You know me, and you know where I come from? But I have not come of my own accord; he who sent me is true, and him you do not know" (John 7.28). "I know him, for I come from him, and he sent me" (John 7.29).

"He said to them, You are from below, I am from above; you are of this world, I am not of this world" (John 8.23).

"For God so loved the world that he gave his only Son, that whoever believes in him should not perish but have eternal life" (John 3.16).

https://www.youtube.com/watch?v=GHQbcBSG8us

http://godlovesmormons.com/