And that is true. So if someone is disabled from doing something, then they do not have free will. So, for instance, if a person is born with free will, then at conversion is no longer able to perform an action such as turning away from God, then he does not have free will, as God has taken that free will away from him, as would be the case of Eternal Security.
The thing is that God is always going to respect our free will. He will not allow us to be "snatched" from His fold, but this does not mean we may not exit by the door. He will tell us that it is not safe outside the fold, that we will be in danger outside of the fold, but He will not prevent us from giving up on Him. This is evidenced in the life of Judas, but also of the Deacon Nicholas, and four of the Seventy Apostles sent out by Christ. These people showed evidence of being sent by Christ. Judas was a disciple, and nobody can really say he didn't truly believe. What we know is that when it came down to it, at the moment of truth, both Judas AND Peter failed. What differentiated them is that while Peter's remorse led to confession, repentance, and absolution, Judas's remorse led to despair, self-loathing, and eventually suicide. Nicholas was filled with the Spirit in Acts, but in Revelations his followers and he were "hated by God".
This is because, as I stated earlier, salvation is a relationship. Any person can walk away from a relationship before the marriage is completed. Joseph was going to put Mary away silently after betrothal, but never actually did. The fact that he intended to do it meant that it was possible. Before the Marriage Supper of the Lamb, it is possible for a person to leave Christ. For humans, that means at any time on earth. This is what happened to those branches which were cut off. They were part of the tree, at one point truly connected to the Source of Life, but they were removed by the Caretaker. This is speaking of us. We must remain ourselves in the Vine, must maintain that relationship, or else we will lose it, not because we were snatched:
But because we leave. It's not a single bad decision. We don't get up one day and say we're going to turn away from the plow. We don't say we aren't going to love God and neighbor, disobeying God. We do so one small choice at a time. and eventually it has become second nature over time. The alcoholic didn't get up one day and set up the goal to destroy his job, family, and life by giving himself to the drink. A person doesn't say he's going to abuse his Tramadol every day until he has a crippling addiction to opiates.
And just like that, a person doesn't go from being a raised Baptist to being a leader of Fascism in one night. He doesn't go from being a cute kid praising God by singing Jesus Loves Me on the stage to bombing a clinic in one night. That kid most certainly thought he was doing the right thing. Five year olds aren't capable of the kind of subterfuge that would allow that child-like faith to be faked.
Who are we to say that the five year old Timothy McVeigh didn't really love Jesus when he was going daily to church his whole childhood? Or that young Adolf Hitler wasn't sincere in his church life as a child?
Conversion doesn't put you on rails. It is completely possible to leave Christ after one makes a committment. It isn't a comforting truth. It is highly inconvenient. But I would rather have an inconvenient Truth than a convenient lie.