The reason why Jesus said “it is profitable for you that I go away,” was because He was only going away as a human on Earth that they could see with their physical eyes.

However, I am telling you nothing but the truth when I say it is profitable (good, expedient, advantageous) for you that I go away. Because if I do not go away, the Comforter (Counselor, Helper, Advocate, Intercessor, Strengthener, Standby) will not come to you [into close fellowship with you]; but if I go away, I will send Him to you [to be in close fellowship with you].

(John 16:7 AMPC)

The Work of the Holy Spirit (2:29)

The “helper” was to come and “guide you into all the Truth.” Notice that He will be communicating on behalf of the Father and the Son.

But when He, the Spirit of Truth (the Truth-giving Spirit) comes, He will guide you into all the Truth (the whole, full Truth). For He will not speak His own message [on His own authority]; but He will tell whatever He hears [from the Father; He will give the message that has been given to Him], and He will announce and declare to you the things that are to come [that will happen in the future].

(John 16:13 AMPC)

The disciples thought Jesus was going to conquer as a King and set up His Kingdom immediately. They did not understand that He came first as a “suffering servant,” and would later return as a conquering King. In the meantime, He would live in His followers through the presence of the Holy Spirit of God.

Grief will Turn To Joy! (3:10)

For the Father Himself [tenderly] loves you because you have loved Me and have believed that I came out from the Father. I came out from the Father and have come into the world; again, I am leaving the world and going to the Father. His disciples said, Ah, now You are speaking plainly to us and not in parables (veiled language and figures of speech)!

(John 16:27-29 AMPC)