That angel delivered the keys of this apostleship and ministry to Joseph Smith and his brethren, and commanded them to blow the Gospel trump through all the nations of the earth, and to cry to all who love and wait patiently for the appearing of our Lord Jesus Christ, “Come out of her, my people, that ye may not be partakers of her sins and that ye receive not of her plagues.” This was the doctrine of Jesus; this was the cry of John when on the Isle of Patmos. That angel has flown through the midst of heaven having the everlasting Gospel to preach to those who dwell on earth, and his cry was and is, “Come out from Babylon, from pride, from the foolish fashions of the world; come out from the spirit of the world, from the spirit of hatred, anger, malice, wrath, selfishness and every feeling but that is honorable and justified of the heavens. Gather yourselves together! Sanctify the Lord God in your heart.” This was the cry, and it is the cry today, and it will be until the pure in heart are gathered together.
– Brigham Young, 7/17/1870