While here in mortality we must learn 3 things to demonstrate our love and devotion to our Heavenly Father and Jesus Christ.
1. resist Satan. (faith and obedience)
2. master the body. (temperance and sacrifice)
3. submit to God's priestood authority. (meekness and humility)
Sadly, so many honorable can't seem to learn lesson 3. Those who never learn lesson 1 are sons of perdition (satanists) and are destined to reveive wages from the master they serve. Those who never learn lesson 2 are hedonists and are destined for only a Telestial reward. Those who never learn lesson 3 are humanists and are destined for only a Terrestrial reward. Only those who learn all 3 will merit through Christ a Celestial reward and eternal calling.
Imagine you inherited " eternal lives" and were charged with an eternal stewardship to prepare spirits for their own mortality (mortality prep?). Could you effectively help other spirits prepare to learn these lessons of mortality if you yourself never learned them?
32 For behold, this life is the time for men to prepare to meet God; yea, behold the day of this life is the day for men to perform their labors. (Book of Mormon, Alma, Alma 34)