A deeper understanding of the word eternal.  I read a study from Arlen Chitwood, who is a Greek Scholar, that the world eternal as we define it in the English language, was not a part of the Greeks understanding.  They thought in the term of ages.  Everything was looked upon as having a beginning and an end.  If they were going to infer the definition that we now hold to today as eternal, the only way they could express it was to say ages upon ages.  In the light of this, I ask you to reread the talking about loosing your life or soul.  It is in regard to an age.  Which age, the age of the Kingdom of Heaven, that is what is being presented through out the gospels.  Because the Jews rejected this kingdom... Matt. 23 :13, Matt. 21:43. a nation bearing the fruit appropriate for it would be established - hence the age of grace and the calling out of the body of Christ from both the Jew and Gentile nations.    When will that kingdom reign....during the 1000 year reign of Christ from Heaven over the earth.  What is being forfeited...the soul- not the spirit.  Some interesting stuff to think about here.