Jesus was leaving, yes, but would not abandon His disciples as orphans. They had no reason to fear; the Comforter would come. We have much to gain from what Jesus told the disciples.
If ye love me, ye will keep my commandments. And I will pray the Father, and he shall give you another Comforter, that he may be with you for ever, even the Spirit of truth: whom the world cannot receive; for it beholdeth him not, neither knoweth him: ye know him; for he abideth with you, and shall be in you. I will not leave you desolate: I come unto you. Yet a little while, and the world beholdeth me no more; but ye behold me: because I live, ye shall live also. In that day ye shall know that I am in my Father, and ye in me, and I in you. He that hath my commandments, and keepeth them, he it is that loveth me: and he that loveth me shall be loved of my Father, and I will love him, and will manifest myself unto him.
Judas (not Iscariot) saith unto him, Lord, what is come to pass that thou wilt manifest thyself unto us, and not unto the world?
Jesus answered and said unto him, If a man love me, he will keep my word: and my Father will love him, and we will come unto him, and make our abode with him. He that loveth me not keepeth not my words: and the word which ye hear is not mine, but the Father’s who sent me. These things have I spoken unto you, while yet abiding with you. But the Comforter, even the Holy Spirit, whom the Father will send in my name, he shall teach you all things, and bring to your remembrance all that I said unto you. Peace I leave with you; my peace I give unto you: not as the world giveth, give I unto you. Let not your heart be troubled, neither let it be fearful. Ye heard how I said to you, I go away, and I come unto you. If ye loved me, ye would have rejoiced, because I go unto the Father: for the Father is greater than I. And now I have told you before it come to pass, that, when it is come to pass, ye may believe. I will no more speak much with you, for the prince of the world cometh: and he hath nothing in me; but that the world may know that I love the Father, and as the Father gave me commandment, even so I do.
Arise, let us go hence.
But these things have I spoken unto you, that when their hour is come, ye may remember them, how that I told you. And these things I said not unto you from the beginning, because I was with you. But now I go unto him that sent me; and none of you asketh me, Whither goest thou? But because I have spoken these things unto you, sorrow hath filled your heart. Nevertheless I tell you the truth: It is expedient for you that I go away; for if I go not away, the Comforter will not come unto you; but if I go, I will send him unto you. And he, when he is come, will convict the world in respect of sin, and of righteousness, and of judgment: of sin, because they believe not on me; of righteousness, because I go to the Father, and ye behold me no more; of judgment, because the prince of this world hath been judged. I have yet many things to say unto you, but ye cannot bear them now. Howbeit when he, the Spirit of truth, is come, he shall guide you into all the truth: for he shall not speak from himself; but what things soever he shall hear, these shall he speak: and he shall declare unto you the things that are to come. He shall glorify me: for he shall take of mine, and shall declare it unto you. All things whatsoever the Father hath are mine: therefore said I, that he taketh of mine, and shall declare it unto you” (John 14:15-31, 16:4-15).