President John Taylor spoke of power of the atonement over children who have not yet reached the age of accountability,

“Without Adam’s Transgression those children could not have existed; through the atonement they are placed in a state of salvation without any act of their own. These would embrace, according to the opinion of statisticians, more than one-half of the human family, who can attribute their salvation only to the mediation and atonement of the Savior. Thus, as stated elsewhere, in some mysterious, incomprehensible way, Jesus assumed the responsibility which naturally would have devolved upon Adam; but which could only be accomplished through the mediation of Himself, and by taking upon Himself their sorrows, assuming their responsibilities, and bearing their transgressions or sins.”

John Taylor
Teachings of the President of the Church: John Taylor, p. 52

President John Taylor (Third President of the Church) said,

“How consoling it is to those who are called upon to mourn the loss of dear friends in death, to know that we will again be associated with them! How encouragining to all who live accordingly to the revealed rpinciples of truth, perhaps more especially to those whose lives are pretty well spent, who have bourne the heat and burden of the day, to konw that ere long we shall burst the barriers of the tomb, and come forth living and immortal souls, to enjoy the society of our tried and trusted friends, no more to be afflicted with the seeds of death, and to finish the work the Father has given us to do!”

John Taylor, Teachings of the Presidents of the Church: John Taylor, p.50-51.