The hymn Elder Hales quotes in his talk summarizes my thoughts in this manner:
Know this, that ev’ry soul is free
To choose his life and what he’ll be;
For this eternal truth is giv’n:
That God will force no man to heav’n. (Hymn no. 240)
God gave us the freedom to choose which side we’ll take in the pre-mortal existence. Once we made the choice, we became moral agents unto Him and His law. Furthermore, he teaches us that each person born should be free to act upon their covenant and that action will determine their agency.