John Calvin Commentary John 6:20

"But he saith unto them, It is I; be not afraid." — John 6:20 (ASV)

It is I: be not terrified. From this, we learn that it is in Christ’s presence alone that we have abundant grounds for confidence, so that we may be calm and at ease.

But this belongs exclusively to the disciples of Christ, for we will later see that wicked men were struck down by the same words, It is I, (John 18:6). The reason for this distinction is that he is sent as a Judge to the reprobate and unbelievers for their destruction; therefore, they cannot bear his presence without being immediately overwhelmed.

But believers, who know that he is given to them to make propitiation, as soon as they hear his name—which is a sure pledge to them of both God’s love and their salvation—take courage as if they had been raised from death to life; they calmly look at the clear sky, dwell quietly on earth, and, victorious over every calamity, take him for their shield against all dangers.

Not only does he comfort and encourage them by his word, but he also actually removes the cause of the terror by allaying the tempest.