The Core-Part Deux.
The core of an apple is the toughest portion, making it nutrient dense and the place that protects and houses the seeds. When fruit is rotten in it's entirety, it's said to be rotten TO the core, not rotten FROM the core. This denotes that some outside influence infiltrated it, and it didn't begin at its root. It began in its flesh.
Outside issues, situations, and even people can begin to burrow into our flesh, causing parts of us to be unfit for use. The wonderful news is that most circumstances do not shake our foundation, or our core, the place where the seeds of faith and trust reside. They've simply affected our flesh (will, emotions, and desires.)
Those things can be either cut off or fixed, as long as the place where the seed resides is untouched. Even when your flesh is attacked, know that your core remains unblemished, still holding the ability to recreate what's inside of it.