The title of this thread is called "the security of the believer." Your post says that "only believers" can commit apostasy. From putting the title of this thread + your post together you seem to be saying security of the believer is in the hands of the believer. A believer can choose to stay secured or they can "fall away." Am I understanding correctly what you're saying here?
No, you are not understanding at all. The security of the believer is in God's hand, and
His alone. Once saved (born again), we are secure in
Him by
His power for
His purposes. We are secure because His power
CANNOT be overcome by
ANY, including the believer. And while some say we can "jump out of His hand",
He wouldn't allow it, given the price
He paid to secure us, and now that
He OWNS us (and we don't belong to ourselves anymore),
He doesn't allow us to do so. It's
ALL ABOUT HIM, not us. The reason Paul said, "I
could wish that myself were accursed from Christ" (Romans 9:3) is because he knew he
COULD NOT.
Now, on "falling away". As previously stated, those falling away are those who were once loyal, voluntarily and deliberately deserting, defecting, revolting, abandoning their
allegiance. The one "falling away" is
NOT abandoning their
relationship with Him, they are abandoning their
allegiance to Him. This is not about the parent-child relationship, it's about the covenant (marital) relationship. It's
not about salvation, but
service.