Are you afraid?
“Let not your heart be troubled,”
(From the writings of Rev. Dr. John Gill. Gill’s writings are in the Public Domain.)
John 14:1 Let not your heart be troubled 
. . . There were many things which must needs lie heavy upon, and greatly depress the minds of the disciples; most of all the loss of Christ's bodily presence, his speedy departure from them, of which he had given them notice in the preceding chapter; also the manner in which he should be removed from them, and the circumstances that should attend the same, as that he should be betrayed by one of them, and denied by another; likewise the poor and uncomfortable situation they were likely to be left in, without any sight or hope of that temporal kingdom being erected, which they had been in expectation of; and also the issue and consequence of all this, that they would be exposed to the hatred and persecutions of men. Now in the multitude of these thoughts within them, Christ comforts them, bids them be of good heart, and exhorts them to all exercise of faith on God, and on himself, as the best way to be rid of heart troubles, and to have peace:
Ye believe in God, believe also in me
Which words may be read and interpreted different ways: either thus, “ye believe in God, and ye believe in me”; and so are both propositions alike, and express God and Christ to be equally the object of their faith; and since therefore they had so good a foundation for their faith and confidence, they had no reason to be uneasy: or thus, “believe in God, and believe in me”; and so both are exhortations to exercise faith alike on them both, as being the best antidote they could make use of against heart troubles: or thus, “believe in God, and ye believe in me”; and so the former is an exhortation, the latter a proposition: and the sense is, put your trust in God, and you will also trust in me, for I am of the same nature and essence with him; I and my Father are one; so that if you believe in one, you must believe in the other: or thus, and so our translators render them, “ye believe in God, believe also in me”; and so the former is a proposition, or an assertion, and the latter is an exhortation grounded upon it: you have believed in God as faithful and true in all his promises, though yon have not seen him; believe in me also, though I am going from you, and shall be absent for a while; this you may be assured of, that whatever I have said shall be accomplished. The words considered either way are a full proof of the true deity of Christ, since he is represented as equally the object of faith with God the Father, and lay a foundation for solid peace and comfort in a view of afflictions and persecutions in the world.
 John Gill, “John 14:1,” John Gill’s Exposition of the Old & New Testament, Vol. 8 (London: Mathews & Leigh, 1809; reprint, Paris, AR.: The Baptist Standard Bearer, 1989), 55-56 (page citations are to the reprint edition).