And this is the path where this heretical doctrine leads to. Certainly if you can "choose" to follow Christ then you can "choose" not to follow Him at some point in future. This, of course, forgets the fact that we become "bond servants" of God, adopted into His family, joint heirs with Christ, children of the light, etc.
So safely are we kept, how can we possibly be taken away? Satan would have to go through Christ and God the Father in order to snatch our life away.