Revelations of the Prophet Joseph Smith, pg. 353; “Under these conditions President Spencer W. Kimball began an exhaustive personal study of the scriptures as well as statements of Church leaders since Joseph Smith, and asked other General Authorities to share their personal feelings relative to the longstanding Church policy. Then he began to inquire of the Lord if the time was not right to extend the priesthood blessings to this restricted people. Recalling this period, President Kimball stated, “Day after day, and especially on Saturdays and Sundays when there were no organizations in the temple, I went there when I could be alone.” The result was a revelation on 1 June 1978.”
Romans 12:2; “And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.”
Truth: the Mormon Church was being pressured by many to change their racist ways. One example was the NCAA who was threatening to boycott the BYU football team.