The Language of Salvation: Sanctification

Is the Christian life just "fire insurance", or is there a true process in which God purposely makes us more like Him in this world, and prepares us for the world to come?  The Bible is pretty clear that all Christians are separated by God from this world to Himself, to be a witness in this fallen world.  And this process of separating ourselves from sin and to God is called "sanctification."  It is not an easy or fun process, but it is necessary.