In the New Testament, Jesus Christ frequently alludes to His impending departure from the world, a theme that is particularly prominent in the Gospel of John. This departure encompasses His crucifixion, resurrection, and ascension into heaven. These discussions are pivotal as they prepare His disciples for the events that will soon unfold and the new phase of their mission without His physical presence.

John 13:31-33
In the Upper Room, after Judas Iscariot leaves to betray Him, Jesus begins to speak openly about His departure. He says, "Now the Son of Man is glorified, and God is glorified in Him" (John 13:31). Here, Jesus indicates that His glorification is imminent, referring to His crucifixion as the means by which God's redemptive plan will be fulfilled. He continues, "Little children, I am with you only a little while longer. You will look for Me, and as I said to the Jews, so now I say to you: ‘Where I am going, you cannot come’" (John 13:33). This statement underscores the necessity of His departure and the disciples' current inability to follow Him to the cross and beyond.

John 14:1-4
In comforting His disciples, Jesus assures them of His continued care and the future reunion. He declares, "Do not let your hearts be troubled. You believe in God; believe in Me as well. In My Father’s house are many rooms; if it were not so, would I have told you that I am going there to prepare a place for you?" (John 14:1-2). Jesus emphasizes His departure as a preparatory act for the disciples' eternal dwelling with Him. He promises, "And if I go and prepare a place for you, I will come back and welcome you into My presence, so that you also may be where I am" (John 14:3). This assurance highlights the eschatological hope of His return and the ultimate fulfillment of His kingdom.

John 16:5-7
Further elucidating the necessity of His departure, Jesus explains, "But now I am going to Him who sent Me, yet none of you asks Me, ‘Where are You going?’ Instead, your hearts are filled with sorrow because I have told you these things. But I tell you the truth, it is for your benefit that I am going away. Unless I go away, the Advocate will not come to you; but if I go, I will send Him to you" (John 16:5-7). Here, Jesus introduces the coming of the Holy Spirit, the Advocate, whose presence will empower the disciples to continue His work on earth. The departure is thus portrayed as advantageous, ensuring the continuation and expansion of His ministry through the Spirit.

Acts 1:9-11
The culmination of Jesus' departure is His ascension, as recorded in the Book of Acts. "After He had said this, they watched as He was taken up, and a cloud hid Him from their sight. They were looking intently into the sky as He was going, when suddenly two men dressed in white stood beside them. 'Men of Galilee,' they said, 'why do you stand here looking into the sky? This same Jesus, who has been taken from you into heaven, will come back in the same way you have seen Him go into heaven'" (Acts 1:9-11). The ascension marks the physical departure of Jesus from the earth, yet it also affirms His promised return, reinforcing the hope and mission entrusted to His followers.

Throughout these passages, Jesus' discussions of His departure are not merely about leaving but are deeply intertwined with His mission, the coming of the Holy Spirit, and the promise of His return. These teachings are foundational for understanding the transition from Jesus' earthly ministry to the era of the Church, empowered by the Holy Spirit to carry forth the Gospel to all nations.