Answer:
A spiritual well being is one who walk the spiritual path, where we go beyond the physical body to the inner spirit. Individual (self) is just imagination, an illusion, a bubble. Our body is just a composite of the basic elements (air,fire,water,earth). Due to the friction amongst these elements the body is every changing and therefore is only tempoary; they have birth and death; impermanent.
The inner spirit, the spiritual heart, the 'soul', is the divinity residing within; the voice of 'truth' inside, is alway one and unchanging.
On the spiritual path we rise beyond the divinity in our heart (inner spirit) to connect with the supreme spirit, the all-pervasive reality, the unchanging absolute, the Creator, God, Emptiness, the True Nature, the source,etc.
Another view: When one has a true genuine faith based on the inspired Word, not based upon a feeling or so called inspired Bibles (translations) for a lie. A genuine spiritual well-being inner peace for the true Jesus is almost impossible today due to using his name and person but, unknowingly, is Rev.13:14b.