You need clear, energetic minds, in order to appreciate the exalted character of the truth, to value the atonement, and to place the right estimate upon eternal things. If you pursue a wrong course and indulge in wrong habits of eating, and thereby weaken the intellectual powers, you will not place that high estimate upon salvation and eternal life which will inspire you to conform your life to the life of Christ; you will not make those earnest, self-sacrificing efforts for entire conformity to the will of God which His word requires and which are necessary to give you a moral fitness for the finishing touch of immortality.—Testimonies for the Church 2:66 (1868).
(CH 566.4)