This is a very interesting statement of truth and a reality check of sorts for me. In the latter end of verse 34, Amulek states that the same spirit which possesses our bodies presently will be the same spirit that possesses our body in the eternal world.
Therefore, this speaks volumes to the need for self improvement, discipline, and repentance, turning to God to access our real purpose in all this mortality. It is ensuring that we endure in Christ to the end for which we were created.