Christ’s infinite atonement frees us from the fall of Adam and allows us to exercise our agency in choosing right and wrong. The term, “free agency” is redundant. It is not found in the scriptures. Rather, the scriptures use the term, “agency of man” (Moses 4:3). People only remain free as long as they exercise this agency wisely. Lehi makes it clear that if they choose the plan of Satan, they are choosing captivity and death (2 Nephi 2:27). Thus, the wicked voluntarily give up their freedom so that Satan can drag them down to his miserable level.
Joshua tried to help the children of Israel decide how to use their agency righteously, choose you this day whom ye will serve; whether the gods which your fathers served that were on the other side of the flood, or the gods of the Amorites, in whose land ye dwell: but as for me and my house, we will serve the Lord (Josh 24:15). It is only through serving the Lord that we remain free, for we are able to avoid the bondage of sin and the captivity of the devil.
Brigham Young
"All rational beings have an agency of their own; and according to their own choice they will be saved or damned (DBY, 62).
"Can the people understand that it is actually necessary for opposite principles to be placed before them, or this state of being would be no probation, and we should have no opportunity for exercising the agency given us? Can they understand that we cannot obtain eternal life unless we actually know and comprehend by our experience the principle of good and the principle of evil, the light and the darkness, truth, virtue, and holiness,—also vice, wickedness, and corruption? (DBY, 66).
"Man can produce and control his own acts, but he has no control over their results (DBY, 63).
"There are limits to agency, and to all things and to all beings, and our agency must not infringe upon that law. A man must choose life or death [see Helaman 14:31], and if he chooses death he will find himself abridged, and that the agency which is given to him is so bound up that he cannot exercise it in opposition to the law, without laying himself liable to be corrected and punished by the Almighty. (DBY, 63).
"A man can dispose of his agency or of his birthright, as did Esau of old, but when disposed of, he cannot again obtain it; consequently, it behooves us to be careful, and not forfeit that agency that is given to us. The difference between the righteous and the sinner, eternal life or death, happiness or misery, is this, to those who are exalted there are no bounds or limits to their privileges, their blessings have a continuation, and to their kingdoms, thrones, and dominions, principalities, and powers there is no end, but they increase through all eternity; whereas, those who reject the offer, who despise the proffered mercies of the Lord, and prepare themselves to be banished from his presence, and to become companions of the devils, have their agency abridged immediately, and bounds and limits are put to their operations (DBY, 63-4)
“In rendering that strict obedience, are we made slaves? No, it is the only way on the face of the earth for you and me to become free (DBY, 225)” (Teachings of Presidents of the Church: Brigham Young, pp. 71-3)