Hi! True, there needs to be a change of mind, in order for repentance to begin! I realize that some sincere Christians think it isn't possible for a true Christian to fall away. But I've been taught otherwise, and know of the scriptures that support the truth that some do fall away. No one helplessly falls away - it only happens when intentionally done.
Notice in the following scripture passage, it contains the phrase, "IF you remain faithful to the end" (this shows that not necessarily all will choose to be faithful to the end).
Heb 3:6-8
6 But Christ as a son over his own house; whose house are we, if we hold fast the confidence and the rejoicing of the hope firm unto the end.
7 Wherefore (as the Holy Ghost saith, To day if ye will hear his voice,
8 Harden not your hearts, as in the provocation, in the day of temptation in the wilderness:
KJV