As this physical frame is the throne of the inner temple, whatever occurs to the former is felt by the latter. In reality that which takes delight in joy or is saddened by pain is the inner temple of the body, not the body itself. Since this physical body is throne whereon the inner temple is established, God hath ordained that the body be preserved to the extent possible, so that nothing that causeth repugnance may be experienced. The inner temple beholdeth its physical frame, which is its throne. Thus, if the latter is accorded respect, it is as if the former is the recipient. The converse is likewise true.
(The Báb, Selections from the Writings of the Báb, p. 95)

For the body of man is accidental; it is of no importance. The time of its disintegration will inevitably come. But the spirit of man is essential and therefore eternal. It is a divine bounty. It is the effulgence of the Sun of Reality and therefore of greater importance than the physical body.
(‘Abdu’l-Bahá, Bahá’í World Faith, p. 262)

Furthermore, although all created things grow and develop, yet are they subjected to influences from without. For instance, the sun giveth heat, the rain nourisheth, the wind bringeth life, so that man can develop and grow. Thus it is clear that the human body is under influences from the outside, and that without those influences man could not grow.
(‘Abdu’l-Bahá, Selections from the Writings of ‘Abdu’l-Bahá, p. 48)

In the same way consider the body of man. It must be composed of different organs, parts and members. Human beauty and perfection require the existence of the ear, the eye, the brain and even that of the nails and hair; if man were all brain, eyes or ears, it would be equivalent to imperfection. So the absence of hair, eyelashes, teeth and nails would be an absolute defect, though in comparison with the eye they are without feeling, and in this resemble the mineral and plant; but their absence in the body of man is necessarily faulty and displeasing.
(‘Abdu’l-Bahá, Some Answered Questions, p. 129)

It matters not what the exterior may be if the heart be pure and white within. God does not behold differences of hue and complexion; He looks at the hearts. He whose morals and virtues are praiseworthy is preferred in the presence of God; he who is devoted to the Kingdom is most beloved.
(‘Abdu’l-Bahá, Bahá’í World Faith - ‘Abdu’l-Bahá Section, p. 267)

Observe the human body, its limbs, its members, the eye, the ear, the organs of smell, of taste, the hands, the fingernails. Notwithstanding the differences among all these parts, each one within the limitations of its own being participateth in a coherent whole. If one of them faileth it must be healed, and should no remedy avail, that part must be removed.
(‘Abdu’l-Bahá, Selections from the Writings of ‘Abdu’l-Bahá, p. 190)

So bodily power is not only defective in relation to spiritual power; it is weakness in comparison. In the same way, physical life, in comparison with eternal life in the Kingdom, is considered as death.
(‘Abdu’l-Bahá, Some Answered Questions, p. 126)

The powers of the sympathetic nerve are neither entirely physical nor spiritual, but are between the two (systems). [1] The nerve is connected with both. Its phenomena shall be perfect when its spiritual and physical relations are normal. [1 Answer to question of a physician regarding the sympathetic nervous system of the human organism.] (‘Abdu’l-Bahá, Tablets of ‘Abdu’l-Bahá v2, p. 309)

Verily, I read thy recent letter which showed thy strong love, thy being ablaze with the fire of the love of thy Lord, the Mighty, the Praised, and the penetration of the Spirit of Truth in thy limbs, nerves, veins, arteries, bones, blood and flesh, until it hath taken the reins of power from thy hands and moveth thee as it willeth, causeth thee to speak in what it willeth and attracted thee as it willeth. This is becoming of whatever heart is replenished with the spirit of the love of God.
(‘Abdu’l-Bahá, Tablets of ‘Abdu’l-Bahá v3, p. 716)