God gave his children their free agency even in the spirit world, by which the individual spirits had the privilege, just as men have here, of choosing the good and rejecting the evil, or partaking of the evil to suffer the consequences of their sins. Because of this, some even there were more faithful than others in keeping the commandments of the Lord. Some were of greater intelligence than others, as we find it here, and were honored accordingly. . . .
The spirits of men had their free agency, some were greater than others, and from among them the Father called and foreordained his prophets and rulers. Jeremiah and Abraham were two of them. . . . The spirits of men were not equal. They may have had an equal start, and we know they were all innocent in the beginning; but the right of free agency which was given to them enabled some to outstrip others, and thus, through the eons of immortal existence, to become more intelligent, more faithful, for they were free to act for themselves, to think for themselves, to receive the truth or rebel against it.
(Joseph Fielding Smith, Doctrines of Salvation, 1:58–59)