Will all that are lost be saved? In Luke 15, Jesus gives one parable of a man that lost 1/100 sheep, and rejoiced when that sheep was found. And another parable of a woman who lost 1/10 silver coins, and rejoices much when she finds her lost coin.  

In order for something to be "lost", it must be in one's possession at some point beforehand; and these parables confirm that in the sense of salvation. So, in regards to this, I have a two part question: Will all that are "lost" be saved? And in what sense were we previously in the Father's possession? Is there any scripture that talks about this?  

I know my 2nd question could mean those who had previously come to God, but have fallen away, and came to God again, but I think He is particularly talking about those who have not yet come to God. I think this could be clarified when Jesus says He came to seek that which was lost in relation to a Chief tax collector.
Christ's parables can be dangerous to interpret outside of the interpretation given in the context.  In almost every case there is one thing taught in a parable and everything else is just filler.  The term "parable" can be loosely translated "to throw alongside", the idea is that a story is thrown alongside a single truth.  In this context the teaching is: 


  Luke 15:10 There is joy in the presence of the angels of God over one sinner
  who repents. 


I do not believe that the 99 or the 9 can be tied to any specific group.  What Christ is teaching is that even the most "insignificant" sinner is worth everything in the eyes of God.