Christians agree with Moroni 8:18; Why don't Mormons?

References

[1] Moroni 8:18; Book of Mormon
"For I know that God is not a partial God, neither a changeable being; but he is unchangeable from all eternity to all eternity."

[2] Lorenzo Snow; “The Grand Destiny of Man,” Deseret Evening News, July 20, 1901, 22
"As man is God once was; as God is man may be"

[3] Joseph Smith Quote; History of the Church, Vol. 6, Ch. 14, p. 305-6; Joseph Smith, Jr. "King Follet Discourse"
"God himself was once as we are now, and is an exalted man, and sits enthroned in yonder heavens!  That is the great secret. ...I am going to tell you how God came to be God.  We have imagined and supposed that God was God from all eternity.  I will refute that idea, and take away the veil,..."

See also:

http://WeAgreeWith818.com
Isaiah 44:6,8 
Romans 11:33-36

A Mormon Testimony is 60% "The Church", not Christ Focused

References

[1] Testimony Glove, Liahona, Oct. 2008
[2] John 14:6 NIV

Prescriptive LDS Testimony:

• 1. I know that God is our Heavenly Father and He loves us.
• 2. I know that His Son, Jesus Christ, is our Savior and Redeemer.
• 3. I know that Joseph Smith is a prophet of God. He restored the gospel of Jesus Christ to the earth and translated the Book of Mormon by the power of God.
• 4. I know that The Church of Jesus Christ of Latter-day Saints is the Lord’s Church on the earth today.
• 5. I know that this Church is led by a living prophet who receives revelation.

References:
John 14:6 NIV
http://www.lds.org/liahona/2008/10/testimony-glove