John Calvin Commentary John 11:26

"and whosoever liveth and believeth on me shall never die. Believest thou this?" — John 11:26 (ASV)

And whoever lives and believes in me. This is the exposition of the second clause, how Christ is the life; and he is so, because he never permits the life which he has once bestowed to be lost, but preserves it to the end. For since flesh is so frail, what would become of people, if, after having once obtained life, they were afterwards left to themselves? The perpetuity of the life must, therefore, be founded on the power of Christ himself, that he may complete what he has begun.

Shall never die. The reason why it is said that believers never die is that their souls, being born again of incorruptible seed (1 Peter 1:23), have Christ dwelling in them, from whom they derive perpetual vigor; for, though the body be subject to death on account of sin,
yet the spirit is life on account of righteousness (Romans 8:10).

That the outward man daily decays in them is so far from taking anything away from their true life, that it aids its progress, because the inward man is renewed from day to day (2 Corinthians 4:16). What is still more, death itself is a sort of emancipation from the bondage of death.

Do you believe this? Christ seems, at first sight, to discourse about spiritual life, for the purpose of withdrawing Martha’s mind from her present desire. Martha wished that her brother should be restored to life. Christ replies that he is the Author of a more excellent life; and that is because he quickens the souls of believers by divine power. Yet I have no doubt that he intended to include both favors; therefore, he describes in general terms the spiritual life that he bestows on all his followers, but also wishes to give them an opportunity of knowing this power, which he would soon manifest in raising Lazarus.