Life is like an old iron bed, firm on both ends but saggy in the middle.
 So is the life of most believers.  We know we are saved and going to heaven, but what about the saggy middle?  Once we are born from above we are sent out to do the best we can until we die.  I am not satisfied with a saggy middle.  I have found a security in Christ that has shored up the middle.  Knowing that my sins are forgiven by the blood of the spotless lamb, Jesus is wonderful. He has redeemed us from our unrighteous acts by His blood. But, that's not all He accomplished for us on the cross.  He died as us, putting to death our old man adam, the nature of sin (the thing that caused sin in the first place).  So NOW, it's not my nature to sin anymore.  I am free from the old life of sin and unrighteousness and am set free with His life of righteousness.  I am now a partaker of HIS divine nature.  Just as sin separated me from God, so righteousness separates me from sin.  So, this present life is not tying to overcome sin and it's condemnation.
 It is now secure and steadfast, knowing that this present life I live is not my own, but His.  Therefore I can't fail with His life as mine.  He has already overcome! I am just allowing Him to live out that overcoming life through me, as me.