Amy,
 
I like the scriptural quote you used in your post on overcomers:
 
 
The "overcomer" is plainly defined in Scripture, as follows:

1 John 5:4-5 For whatever is born of God overcomes the world. And this is the victory that has overcome the world -our faith. Who is he who overcomes the world, but he who believes that Jesus is the Son of God?

The very first act of overcoming a Christian participates in is personal identity with the world has changed in Gods view, to an identity with Christ.  What a marvelous overcoming that is.....but is that all?  Within this new identity, the body of Christ, we have things to overcome as well because we can at any given moment, as we interact with fellow believers, choose to act in the identity of the world or act in our new identity with Christ.   As a new creation, We have the obligation to overcome the patterns of our past through Christs present day continual washing with his word, our acknowledging and dealing with that which the water has cleared to our vision, and the choice to go forward from that learning point.  Are there those that don't bother or don't know to bother  ....yes.  Are there those that try and in their own strength find it impossible, so live defeated, yes.  Are there those, who by the grace of God, learn to turn to him and together they overcome the old nature by  choosing to live from the right nature by making Holy choices and then decisions...yes.   This is an on going process and we can suffer defeat during the process by not understanding the importance of carry on.  Chapters 2 and 3 of Revelation show specific areas where a Christian through ignorance or through laziness, can be overcome.  Very likely, they haven't a clue that there is a contest for their new life in Christ going on.  This new life brings the hope of an active intimate life with Christ and the Father not only during the millineal reign of Christ but out into the ages beyond.  Can it be forfeited?  Rev. 2,3 say yes.